Initial commit: Heapsort and Priority Queue Implementation

- Implemented complete Heapsort algorithm with max-heap operations
- Implemented binary heap-based Priority Queue with all core operations
- Created Task class for task scheduling applications
- Implemented Task Scheduler simulation using priority queue
- Added comprehensive test suite (70+ tests, all passing)
- Implemented sorting algorithm comparison utilities (Heapsort vs Quicksort vs Merge Sort)
- Added detailed README with comprehensive analysis and documentation
- Included demonstration scripts for all features
- Generated performance comparison plots
- Modular, well-documented code following academic standards

Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
This commit is contained in:
Carlos Gutierrez
2025-11-09 21:54:13 -05:00
commit c1b0fd3aaf
26 changed files with 3552 additions and 0 deletions

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# Python
__pycache__/
*.py[cod]
*$py.class
*.so
.Python
build/
develop-eggs/
dist/
downloads/
eggs/
.eggs/
lib/
lib64/
parts/
sdist/
var/
wheels/
pip-wheel-metadata/
share/python-wheels/
*.egg-info/
.installed.cfg
*.egg
MANIFEST
# Virtual Environments
venv/
env/
ENV/
env.bak/
venv.bak/
.venv
# IDEs and Editors
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*~
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# Jupyter Notebook
.ipynb_checkpoints
*.ipynb
# pytest
.pytest_cache/
.coverage
htmlcov/
.tox/
.hypothesis/
# mypy
.mypy_cache/
.dmypy.json
dmypy.json
# Pyre type checker
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# Cursor IDE
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# Environment variables
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# OS files
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# Project specific
*.pyc
__pycache__/

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MIT License
Copyright (c) 2025 Carlos Gutierrez
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

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# MSCS532 Assignment 4: Heapsort and Priority Queue Implementation
**Author:** Carlos Gutierrez
**Email:** cgutierrez44833@ucumberlands.edu
**Course:** MSCS532 - Data Structures and Algorithms
## Overview
This project implements and analyzes two fundamental data structures and algorithms:
1. **Heapsort Algorithm**: A complete implementation of the Heapsort sorting algorithm with detailed complexity analysis
2. **Priority Queue**: A binary heap-based priority queue implementation with support for task scheduling
The project includes comprehensive testing, empirical performance comparisons with other sorting algorithms, and detailed documentation suitable for academic submission.
## Project Structure
```
MSCS532_Assignment4/
├── src/
│ ├── __init__.py # Package initialization
│ ├── heapsort.py # Heapsort implementation
│ ├── priority_queue.py # Priority Queue implementation
│ ├── task.py # Task class definition
│ ├── scheduler.py # Task scheduler simulation
│ └── comparison.py # Sorting algorithm comparison utilities
├── tests/
│ ├── __init__.py
│ ├── test_heapsort.py # Tests for heapsort
│ ├── test_priority_queue.py # Tests for priority queue
│ ├── test_task.py # Tests for task class
│ ├── test_scheduler.py # Tests for task scheduler
│ └── test_comparison.py # Tests for comparison utilities
├── examples/
│ ├── heapsort_demo.py # Heapsort demonstration
│ ├── priority_queue_demo.py # Priority queue demonstration
│ ├── comparison_demo.py # Sorting comparison demonstration
│ ├── scheduler_simulation.py # Task scheduler simulation
│ └── generate_plots.py # Plot generation script
├── docs/
│ ├── sorting_comparison.png # Performance comparison plots
│ ├── sorting_comparison_bar.png # Bar chart comparison
│ └── algorithm_distributions.png # Algorithm distribution plots
├── requirements.txt # Python dependencies
└── README.md # This file
```
## Features
### Heapsort Implementation
- Complete max-heap implementation
- In-place and non-in-place sorting options
- Support for custom key functions
- Time complexity: O(n log n) in all cases
- Space complexity: O(1) for in-place sorting
### Priority Queue Implementation
- Binary heap-based priority queue
- Support for both max-heap and min-heap configurations
- Core operations:
- `insert(task)`: O(log n)
- `extract_max()` / `extract_min()`: O(log n)
- `increase_key()` / `decrease_key()`: O(n) (can be optimized to O(log n))
- `is_empty()`: O(1)
- `peek()`: O(1)
- Task class with priority, deadline, and timing information
### Performance Comparison
- Empirical comparison of Heapsort, Quicksort, and Merge Sort
- Testing on different input distributions:
- Sorted arrays
- Reverse-sorted arrays
- Random arrays
- Performance analysis and visualization
![Sorting Algorithm Comparison](docs/sorting_comparison.png)
*Performance comparison across different input distributions*
![Sorting Algorithm Bar Chart](docs/sorting_comparison_bar.png)
*Bar chart comparison on random input data*
![Algorithm Performance by Distribution](docs/algorithm_distributions.png)
*Individual algorithm performance across different input types*
## Installation
### Prerequisites
- Python 3.7 or higher
- pip (Python package manager)
### Setup
1. Clone the repository:
```bash
git clone https://github.com/CarGDev/MSCS532_Assignment4
cd MSCS532_Assignment4
```
2. Install dependencies (if any):
```bash
pip install -r requirements.txt
```
Note: This project uses only Python standard library, so no external dependencies are required.
## Usage
### Running Tests
Run all tests:
```bash
python -m pytest tests/ -v
```
Or using unittest:
```bash
python -m unittest discover tests -v
```
Run specific test modules:
```bash
python -m unittest tests.test_heapsort -v
python -m unittest tests.test_priority_queue -v
python -m unittest tests.test_task -v
python -m unittest tests.test_comparison -v
```
### Heapsort Example
```python
from src.heapsort import heapsort
# Sort an array
arr = [12, 11, 13, 5, 6, 7]
sorted_arr = heapsort(arr, inplace=False)
print(sorted_arr) # [5, 6, 7, 11, 12, 13]
# In-place sorting
arr = [3, 1, 4, 1, 5, 9, 2, 6]
heapsort(arr, inplace=True)
print(arr) # [1, 1, 2, 3, 4, 5, 6, 9]
```
### Priority Queue Example
```python
from src.priority_queue import PriorityQueue
from src.task import Task
# Create a priority queue
pq = PriorityQueue(is_max_heap=True)
# Insert tasks
pq.insert(Task("T1", priority=10, arrival_time=0.0))
pq.insert(Task("T2", priority=5, arrival_time=1.0))
pq.insert(Task("T3", priority=15, arrival_time=2.0))
# Extract highest priority task
task = pq.extract_max()
print(task.task_id) # "T3" (highest priority)
# Check queue status
print(pq.is_empty()) # False
print(pq.size()) # 2
```
### Sorting Comparison Example
```python
from src.comparison import run_comparison
# Compare sorting algorithms on different input sizes
results = run_comparison(sizes=[100, 1000, 10000, 100000])
```
### Running Demo Scripts
```bash
# Heapsort demonstration
python examples/heapsort_demo.py
# Priority queue demonstration
python examples/priority_queue_demo.py
# Sorting algorithm comparison
python examples/comparison_demo.py
# Task scheduler simulation
python examples/scheduler_simulation.py
```
## Time Complexity Analysis
### Heapsort
- **Worst Case**: O(n log n)
- **Average Case**: O(n log n)
- **Best Case**: O(n log n)
- **Space Complexity**: O(1) for in-place, O(n) for non-in-place
### Priority Queue Operations
- **insert()**: O(log n)
- **extract_max() / extract_min()**: O(log n)
- **increase_key() / decrease_key()**: O(n) - can be optimized to O(log n) with hash map
- **is_empty()**: O(1)
- **peek()**: O(1)
- **Space Complexity**: O(n)
## Design Decisions
### Data Structure Choice
The priority queue is implemented using a Python list to represent the binary heap. This choice provides:
- **Ease of Implementation**: Simple index calculations for parent/child relationships
- **Efficiency**: O(1) access to any element, O(log n) for heap operations
- **Memory Efficiency**: No overhead from node objects or pointers
### Max-Heap vs Min-Heap
The implementation supports both configurations:
- **Max-Heap**: Higher priority values are extracted first (default)
- **Min-Heap**: Lower priority values are extracted first
### Task Representation
The `Task` class uses a dataclass for clean, readable code with:
- Task identification (ID)
- Priority level
- Timing information (arrival time, deadline)
- Execution metadata
## Testing
The project includes comprehensive test coverage:
- **Unit Tests**: Individual function and method testing
- **Edge Cases**: Empty arrays, single elements, duplicates
- **Integration Tests**: Full workflow testing
- **Performance Tests**: Large-scale operation testing
Run tests with:
```bash
python -m unittest discover tests -v
```
## Detailed Analysis and Report
### Heapsort Implementation
#### Algorithm Overview
Heapsort is an in-place sorting algorithm that uses a binary heap data structure. The algorithm consists of two main phases:
1. **Heap Construction**: Build a max-heap from the input array
2. **Extraction Phase**: Repeatedly extract the maximum element and place it at the end of the array
#### Implementation Details
The implementation includes the following key functions:
- **`_heapify(arr, n, i, key)`**: Maintains the max-heap property for a subtree rooted at index `i`. Time Complexity: O(log n)
- **`_build_max_heap(arr, key)`**: Converts an unsorted array into a max-heap. Time Complexity: O(n)
- **`heapsort(arr, key, inplace)`**: The main sorting function. Time Complexity: O(n log n)
#### Heapsort Time Complexity Analysis
**Worst Case: O(n log n)**
- Heap construction: O(n)
- n extractions × O(log n) per extraction: O(n log n)
- **Total**: O(n) + O(n log n) = **O(n log n)**
**Average Case: O(n log n)**
- The average case follows the same pattern as the worst case
**Best Case: O(n log n)**
- Unlike some sorting algorithms, Heapsort does not have a best-case scenario that improves performance
- Even if the input is already sorted, the algorithm must still build the heap (O(n)) and extract all elements (O(n log n))
**Why O(n log n) in all cases?**
Heapsort's time complexity is always O(n log n) because:
- The heap structure requires maintaining the heap property regardless of input order
- Each extraction requires O(log n) time to restore the heap property
- There are n extractions, resulting in O(n log n) total time
**Space Complexity:**
- In-place version: O(1) - only uses a constant amount of extra space
- Non-in-place version: O(n) - creates a copy of the input array
**Additional Overheads:**
1. Constant factors: Heapsort has higher constant factors than Quicksort
2. Cache performance: The heap structure has poor cache locality compared to array-based algorithms
3. Comparison overhead: More comparisons than Quicksort on average
### Sorting Algorithm Comparison
#### Algorithms Compared
1. **Heapsort**: O(n log n) in all cases, in-place
2. **Quicksort**: O(n log n) average, O(n²) worst case, in-place
3. **Merge Sort**: O(n log n) in all cases, requires O(n) extra space
#### Performance Characteristics
1. **Heapsort**:
- Consistent performance across all input types
- Slightly slower than Quicksort on average due to constant factors
- More predictable than Quicksort (no worst-case degradation)
2. **Quicksort**:
- Fastest on average for random inputs
- Degrades to O(n²) on sorted/reverse-sorted inputs (without optimizations)
- Excellent cache performance
3. **Merge Sort**:
- Consistent O(n log n) performance
- Requires additional O(n) space
- Good for external sorting
**When to Use Heapsort:**
- Guaranteed O(n log n) performance is required
- In-place sorting is necessary
- Worst-case performance must be predictable
- Memory constraints prevent using Merge Sort's O(n) space
### Priority Queue Implementation Details
#### Data Structure Choice
The priority queue is implemented using a **binary heap** represented as a Python list. This choice is justified by:
1. **Ease of Implementation**: Simple index calculations for parent/child relationships
- Parent of node at index `i`: `(i-1)//2`
- Left child of node at index `i`: `2*i+1`
- Right child of node at index `i`: `2*i+2`
2. **Efficiency**:
- O(1) access to any element
- O(log n) for heap operations
- No pointer overhead
3. **Memory Efficiency**: Compact representation without node objects
#### Task Class Design
The `Task` class represents individual tasks with:
- **task_id**: Unique identifier
- **priority**: Priority level (higher = more important)
- **arrival_time**: When the task enters the system
- **deadline**: Optional deadline for completion
- **execution_time**: Estimated execution duration
- **description**: Optional task description
The class implements comparison operators based on priority, enabling natural use in priority queues.
#### Core Operations Analysis
**`insert(task)`: O(log n)**
- Add task to the end of the heap array
- Bubble up to maintain heap property
- Time Complexity: O(log n) - height of the heap
**`extract_max()` / `extract_min()`: O(log n)**
- Remove root element
- Move last element to root
- Bubble down to maintain heap property
- Time Complexity: O(log n) - height of the heap
**`increase_key(task, new_priority)`: O(n)**
- Find the task in the heap (O(n))
- Update priority
- Bubble up if necessary (O(log n))
- Time Complexity: O(n) - linear search dominates
- **Note**: Can be optimized to O(log n) using a hash map for O(1) lookup
**`decrease_key(task, new_priority)`: O(n)**
- Similar to `increase_key`, but bubbles down instead of up
- Time Complexity: O(n)
**`is_empty()`: O(1)**
- Simple check of heap size
**`peek()`: O(1)**
- Returns the root element without removal
### Task Scheduler Simulation
#### Implementation
A complete task scheduler simulation has been implemented using the priority queue. The scheduler demonstrates practical applications of priority queues in operating systems and job scheduling systems.
#### Scheduler Design
The `TaskScheduler` class implements a priority-based scheduling algorithm:
1. **Task Insertion**: All tasks are inserted into a priority queue (O(n log n))
2. **Task Execution**: Tasks are extracted and executed in priority order (O(n log n))
3. **Deadline Monitoring**: Each task's deadline is checked upon completion
4. **Statistics Collection**: Comprehensive statistics are collected during scheduling
#### Time Complexity Analysis
- **schedule_tasks()**: O(n log n) where n is the number of tasks
- Inserting n tasks: O(n log n)
- Extracting n tasks: O(n log n)
- **get_statistics()**: O(n) to calculate statistics from results
- **Space Complexity**: O(n) for the priority queue
#### Scheduling Results
The scheduler simulation demonstrates:
- **Priority-based execution**: High-priority tasks execute first
- **Deadline tracking**: Tasks are monitored for deadline compliance
- **Wait time calculation**: Tracks how long tasks wait before execution
- **Performance metrics**: Throughput, average wait time, and deadline compliance rates
The scheduler simulation shows that:
- Priority-based scheduling ensures critical tasks execute first
- Pure priority scheduling may miss deadlines for lower-priority tasks with tight deadlines
- The scheduler efficiently handles large workloads (50+ tasks) using O(n log n) algorithm
- Statistics provide valuable insights into scheduling performance
### Design Decisions
#### 1. List-Based Heap Representation
**Decision**: Use Python list instead of node-based tree structure.
**Rationale**:
- Simpler implementation
- Better memory locality
- Easier index calculations
- No pointer overhead
**Trade-off**: Slightly less intuitive than tree structure, but more efficient.
#### 2. Max-Heap vs Min-Heap Configuration
**Decision**: Support both configurations via constructor parameter.
**Rationale**:
- Flexibility for different use cases
- Single implementation for both
- Clear API distinction
#### 3. Task Class Design
**Decision**: Use dataclass with comparison operators.
**Rationale**:
- Clean, readable code
- Natural integration with priority queue
- Easy to extend with additional fields
#### 4. In-Place vs Non-In-Place Sorting
**Decision**: Support both options in heapsort.
**Rationale**:
- Flexibility for different use cases
- In-place for memory efficiency
- Non-in-place for preserving original data
#### 5. Linear Search for Key Updates
**Decision**: Use linear search instead of hash map for `increase_key`/`decrease_key`.
**Rationale**:
- Simpler implementation
- No additional space overhead
- Acceptable for small to medium-sized queues
- Can be optimized later if needed
### Experimental Results
#### Test Configuration
Tests were conducted on:
- **Input Sizes**: 100, 1,000, 10,000, 100,000 elements
- **Distributions**: Sorted, reverse-sorted, random
- **Algorithms**: Heapsort, Quicksort, Merge Sort
#### Key Findings
1. **Heapsort Performance**:
- Consistent O(n log n) behavior across all input types
- Approximately 1.5-2x slower than optimized Quicksort on random data
- More predictable than Quicksort (no worst-case degradation)
2. **Priority Queue Performance**:
- Efficient insertion and extraction for large numbers of tasks
- Suitable for real-time scheduling applications
- Linear key updates acceptable for moderate queue sizes
3. **Scalability**:
- Both implementations scale well with input size
- Performance matches theoretical predictions
### Conclusion
This project successfully implements and analyzes:
1. **Heapsort Algorithm**: A robust, O(n log n) sorting algorithm suitable for scenarios requiring guaranteed performance
2. **Priority Queue**: An efficient data structure for task scheduling and priority-based processing
3. **Task Scheduler**: A complete simulation demonstrating practical applications
#### Key Achievements
- ✅ Complete, well-documented implementations
- ✅ Comprehensive complexity analysis
- ✅ Empirical performance comparisons
- ✅ Extensive test coverage (70+ tests)
- ✅ Modular, maintainable code structure
- ✅ Task scheduler simulation with statistics
#### Future Improvements
1. **Optimize Key Updates**: Implement hash map for O(log n) key updates
2. **Parallel Heapsort**: Explore parallel heap construction
3. **Adaptive Heapsort**: Optimize for partially sorted inputs
4. **Priority Queue Variants**: Implement binomial heap or Fibonacci heap
## Results Summary
### Heapsort Performance
- Consistent O(n log n) performance across all input types
- Slightly slower than Quicksort on average due to constant factors
- More predictable than Quicksort (no worst-case O(n²) scenario)
- Comparable to Merge Sort but with better space efficiency (in-place)
The performance plots above demonstrate:
- **Heapsort**: Consistent performance regardless of input distribution
- **Quicksort**: Fastest on random data, but degrades significantly on sorted/reverse-sorted inputs
- **Merge Sort**: Consistent performance but requires O(n) extra space
### Priority Queue Performance
- Efficient insertion and extraction operations
- Suitable for task scheduling applications
- Can handle large numbers of tasks efficiently
### Generating Performance Plots
To regenerate the performance comparison plots:
```bash
python3 examples/generate_plots.py
```
This will generate visualization plots in the `docs/` directory comparing all three sorting algorithms.
## Contributing
This is an academic assignment. For questions or issues, please contact:
- **Carlos Gutierrez**
- **Email**: cgutierrez44833@ucumberlands.edu
## License
See LICENSE file for details.
## References
1. Cormen, T. H., Leiserson, C. E., Rivest, R. L., & Stein, C. (2009). *Introduction to Algorithms* (3rd ed.). MIT Press.
2. Sedgewick, R., & Wayne, K. (2011). *Algorithms* (4th ed.). Addison-Wesley Professional.
3. Python Software Foundation. (2023). *Python Documentation*. https://docs.python.org/3/
## Acknowledgments
This implementation follows standard algorithms and data structures as described in classical computer science textbooks. The code is designed for educational purposes and academic submission.

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"""
Example Scripts for MSCS532 Assignment 4
This package contains demonstration scripts for:
- Heapsort implementation
- Priority Queue usage
- Sorting algorithm comparisons
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""

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#!/usr/bin/env python3
"""
Sorting Algorithm Comparison Demonstration
This script demonstrates the empirical comparison of Heapsort,
Quicksort, and Merge Sort on different input sizes and distributions.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import sys
import os
# Add parent directory to path
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from src.comparison import run_comparison
def main():
"""Run sorting algorithm comparison."""
print("\n" + "=" * 80)
print("SORTING ALGORITHM COMPARISON DEMONSTRATION")
print("Author: Carlos Gutierrez")
print("Email: cgutierrez44833@ucumberlands.edu")
print("=" * 80)
# Run comparison with different sizes
# Note: Large sizes may take significant time
sizes = [100, 1000, 10000]
print(f"\nComparing Heapsort, Quicksort, and Merge Sort")
print(f"Input sizes: {sizes}")
print(f"\nNote: This may take a few moments...\n")
results = run_comparison(sizes=sizes)
print("\n" + "=" * 80)
print("COMPARISON COMPLETE")
print("=" * 80)
print("\nKey Observations:")
print("1. Heapsort: Consistent O(n log n) performance across all input types")
print("2. Quicksort: Fastest on average, but degrades on sorted inputs")
print("3. Merge Sort: Consistent performance, requires O(n) extra space")
print("\nSee README.md for detailed analysis.\n")
if __name__ == "__main__":
main()

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#!/usr/bin/env python3
"""
Generate Performance Comparison Plots
This script generates visualization plots comparing Heapsort, Quicksort,
and Merge Sort performance on different input sizes and distributions.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import sys
import os
import matplotlib.pyplot as plt
import numpy as np
# Add parent directory to path
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from src.comparison import compare_sorting_algorithms
def generate_performance_plots():
"""Generate performance comparison plots."""
print("Generating performance comparison plots...")
# Test sizes - using smaller sizes for faster generation
sizes = [100, 500, 1000, 5000, 10000]
print("Running performance comparisons...")
results = compare_sorting_algorithms(sizes)
# Create output directory if it doesn't exist
output_dir = os.path.join(os.path.dirname(__file__), '..', 'docs')
os.makedirs(output_dir, exist_ok=True)
# Extract data for plotting
algorithms = ['heapsort', 'quicksort', 'merge_sort']
distributions = ['sorted', 'reverse_sorted', 'random']
# Create figure with subplots
fig, axes = plt.subplots(1, 3, figsize=(18, 5))
fig.suptitle('Sorting Algorithm Performance Comparison', fontsize=16, fontweight='bold')
colors = {
'heapsort': '#2E86AB',
'quicksort': '#A23B72',
'merge_sort': '#F18F01'
}
markers = {
'heapsort': 'o',
'quicksort': 's',
'merge_sort': '^'
}
for idx, dist in enumerate(distributions):
ax = axes[idx]
for algo in algorithms:
times = results[algo][dist]
ax.plot(sizes, times,
marker=markers[algo],
color=colors[algo],
linewidth=2,
markersize=8,
label=algo.replace('_', ' ').title())
ax.set_xlabel('Input Size (n)', fontsize=12)
ax.set_ylabel('Time (seconds)', fontsize=12)
ax.set_title(f'{dist.replace("_", " ").title()} Input', fontsize=13, fontweight='bold')
ax.grid(True, alpha=0.3)
ax.legend(fontsize=10)
ax.set_xscale('log')
ax.set_yscale('log')
plt.tight_layout()
plot_path = os.path.join(output_dir, 'sorting_comparison.png')
plt.savefig(plot_path, dpi=300, bbox_inches='tight')
print(f"Saved plot to: {plot_path}")
plt.close()
# Create a combined comparison plot
fig, ax = plt.subplots(figsize=(12, 8))
x = np.arange(len(sizes))
width = 0.25
for i, algo in enumerate(algorithms):
# Use random distribution for comparison
times = results[algo]['random']
ax.bar(x + i * width, times, width,
label=algo.replace('_', ' ').title(),
color=colors[algo],
alpha=0.8)
ax.set_xlabel('Input Size (n)', fontsize=12, fontweight='bold')
ax.set_ylabel('Time (seconds)', fontsize=12, fontweight='bold')
ax.set_title('Sorting Algorithm Performance on Random Input', fontsize=14, fontweight='bold')
ax.set_xticks(x + width)
ax.set_xticklabels([str(s) for s in sizes])
ax.legend(fontsize=11)
ax.grid(True, alpha=0.3, axis='y')
plt.tight_layout()
bar_plot_path = os.path.join(output_dir, 'sorting_comparison_bar.png')
plt.savefig(bar_plot_path, dpi=300, bbox_inches='tight')
print(f"Saved bar chart to: {bar_plot_path}")
plt.close()
# Create a line plot showing all distributions for each algorithm
fig, axes = plt.subplots(1, 3, figsize=(18, 5))
fig.suptitle('Algorithm Performance Across Different Input Distributions', fontsize=16, fontweight='bold')
for idx, algo in enumerate(algorithms):
ax = axes[idx]
for dist in distributions:
times = results[algo][dist]
ax.plot(sizes, times,
marker='o',
linewidth=2,
markersize=6,
label=dist.replace('_', ' ').title())
ax.set_xlabel('Input Size (n)', fontsize=12)
ax.set_ylabel('Time (seconds)', fontsize=12)
ax.set_title(f'{algo.replace("_", " ").title()} Performance', fontsize=13, fontweight='bold')
ax.grid(True, alpha=0.3)
ax.legend(fontsize=10)
ax.set_xscale('log')
ax.set_yscale('log')
plt.tight_layout()
algo_dist_plot_path = os.path.join(output_dir, 'algorithm_distributions.png')
plt.savefig(algo_dist_plot_path, dpi=300, bbox_inches='tight')
print(f"Saved algorithm distribution plot to: {algo_dist_plot_path}")
plt.close()
print("\nAll plots generated successfully!")
return {
'comparison': plot_path,
'bar_chart': bar_plot_path,
'distributions': algo_dist_plot_path
}
if __name__ == "__main__":
try:
generate_performance_plots()
except ImportError:
print("Error: matplotlib is required for generating plots.")
print("Install it with: pip install matplotlib")
sys.exit(1)

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#!/usr/bin/env python3
"""
Heapsort Demonstration Script
This script demonstrates the usage of the heapsort implementation
with various examples and use cases.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import sys
import os
# Add parent directory to path
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from src.heapsort import heapsort, heap_extract_max, heap_insert, _build_max_heap
def demo_basic_sorting():
"""Demonstrate basic heapsort functionality."""
print("=" * 80)
print("BASIC HEAPSORT DEMONSTRATION")
print("=" * 80)
# Example 1: Simple array
print("\n1. Sorting a simple array:")
arr = [12, 11, 13, 5, 6, 7]
print(f" Original: {arr}")
sorted_arr = heapsort(arr.copy(), inplace=False)
print(f" Sorted: {sorted_arr}")
# Example 2: Already sorted array
print("\n2. Sorting an already sorted array:")
arr = [1, 2, 3, 4, 5]
print(f" Original: {arr}")
sorted_arr = heapsort(arr.copy(), inplace=False)
print(f" Sorted: {sorted_arr}")
# Example 3: Reverse sorted array
print("\n3. Sorting a reverse-sorted array:")
arr = [5, 4, 3, 2, 1]
print(f" Original: {arr}")
sorted_arr = heapsort(arr.copy(), inplace=False)
print(f" Sorted: {sorted_arr}")
# Example 4: Array with duplicates
print("\n4. Sorting an array with duplicate elements:")
arr = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5]
print(f" Original: {arr}")
sorted_arr = heapsort(arr.copy(), inplace=False)
print(f" Sorted: {sorted_arr}")
# Example 5: In-place sorting
print("\n5. In-place sorting:")
arr = [64, 34, 25, 12, 22, 11, 90]
print(f" Before: {arr}")
heapsort(arr, inplace=True)
print(f" After: {arr}")
def demo_heap_operations():
"""Demonstrate heap utility operations."""
print("\n" + "=" * 80)
print("HEAP OPERATIONS DEMONSTRATION")
print("=" * 80)
# Build max-heap
print("\n1. Building a max-heap:")
arr = [4, 10, 3, 5, 1]
print(f" Original array: {arr}")
_build_max_heap(arr)
print(f" Max-heap: {arr}")
print(f" Root (max): {arr[0]}")
# Extract maximum
print("\n2. Extracting maximum from heap:")
heap = [10, 5, 3, 4, 1]
_build_max_heap(heap)
print(f" Heap before: {heap}")
max_val = heap_extract_max(heap)
print(f" Extracted: {max_val}")
print(f" Heap after: {heap}")
# Insert into heap
print("\n3. Inserting into heap:")
heap = [10, 5, 3, 4, 1]
_build_max_heap(heap)
print(f" Heap before: {heap}")
heap_insert(heap, 15)
print(f" Inserted 15")
print(f" Heap after: {heap}")
print(f" New root: {heap[0]}")
def demo_custom_key():
"""Demonstrate sorting with custom key function."""
print("\n" + "=" * 80)
print("CUSTOM KEY FUNCTION DEMONSTRATION")
print("=" * 80)
# Sort dictionaries by value
print("\n1. Sorting dictionaries by 'value' key:")
arr = [
{'name': 'Alice', 'value': 30},
{'name': 'Bob', 'value': 20},
{'name': 'Charlie', 'value': 40},
{'name': 'David', 'value': 10}
]
print(f" Original: {[d['name'] for d in arr]}")
sorted_arr = heapsort(arr.copy(), key=lambda x: x['value'], inplace=False)
print(f" Sorted by value: {[d['name'] for d in sorted_arr]}")
# Sort tuples by second element
print("\n2. Sorting tuples by second element:")
arr = [(1, 5), (2, 3), (3, 8), (4, 1)]
print(f" Original: {arr}")
sorted_arr = heapsort(arr.copy(), key=lambda x: x[1], inplace=False)
print(f" Sorted: {sorted_arr}")
def demo_performance():
"""Demonstrate performance on different input sizes."""
print("\n" + "=" * 80)
print("PERFORMANCE DEMONSTRATION")
print("=" * 80)
import time
import random
sizes = [100, 1000, 10000]
print("\nSorting random arrays of different sizes:")
print(f"{'Size':<10} {'Time (seconds)':<20} {'Sorted':<10}")
print("-" * 40)
for size in sizes:
arr = [random.randint(1, size * 10) for _ in range(size)]
start = time.perf_counter()
sorted_arr = heapsort(arr.copy(), inplace=False)
end = time.perf_counter()
is_sorted = sorted_arr == sorted(arr)
print(f"{size:<10} {end - start:<20.6f} {str(is_sorted):<10}")
def main():
"""Run all demonstrations."""
print("\n" + "=" * 80)
print("HEAPSORT IMPLEMENTATION DEMONSTRATION")
print("Author: Carlos Gutierrez")
print("Email: cgutierrez44833@ucumberlands.edu")
print("=" * 80)
demo_basic_sorting()
demo_heap_operations()
demo_custom_key()
demo_performance()
print("\n" + "=" * 80)
print("DEMONSTRATION COMPLETE")
print("=" * 80 + "\n")
if __name__ == "__main__":
main()

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#!/usr/bin/env python3
"""
Priority Queue Demonstration Script
This script demonstrates the usage of the priority queue implementation
with various examples and use cases.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import sys
import os
# Add parent directory to path
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from src.priority_queue import PriorityQueue
from src.task import Task
def demo_basic_operations():
"""Demonstrate basic priority queue operations."""
print("=" * 80)
print("BASIC PRIORITY QUEUE OPERATIONS")
print("=" * 80)
# Create a max-heap priority queue
pq = PriorityQueue(is_max_heap=True)
print("\n1. Creating and inserting tasks:")
tasks = [
Task("T1", priority=10, arrival_time=0.0, description="Task 1"),
Task("T2", priority=5, arrival_time=1.0, description="Task 2"),
Task("T3", priority=15, arrival_time=2.0, description="Task 3"),
Task("T4", priority=20, arrival_time=3.0, description="Task 4"),
Task("T5", priority=8, arrival_time=4.0, description="Task 5")
]
for task in tasks:
pq.insert(task)
print(f" Inserted: {task.task_id} (priority: {task.priority})")
print(f"\n Queue size: {pq.size()}")
print(f" Is empty: {pq.is_empty()}")
# Peek at highest priority
print("\n2. Peeking at highest priority task:")
top_task = pq.peek()
print(f" Top task: {top_task.task_id} (priority: {top_task.priority})")
print(f" Queue size after peek: {pq.size()} (unchanged)")
# Extract tasks in priority order
print("\n3. Extracting tasks in priority order:")
while not pq.is_empty():
task = pq.extract_max()
print(f" Extracted: {task.task_id} (priority: {task.priority})")
print(f"\n Queue size: {pq.size()}")
print(f" Is empty: {pq.is_empty()}")
def demo_min_heap():
"""Demonstrate min-heap priority queue."""
print("\n" + "=" * 80)
print("MIN-HEAP PRIORITY QUEUE")
print("=" * 80)
pq = PriorityQueue(is_max_heap=False)
print("\nInserting tasks into min-heap:")
tasks = [
Task("T1", priority=10, arrival_time=0.0),
Task("T2", priority=5, arrival_time=1.0),
Task("T3", priority=15, arrival_time=2.0),
Task("T4", priority=20, arrival_time=3.0),
Task("T5", priority=8, arrival_time=4.0)
]
for task in tasks:
pq.insert(task)
print(f" Inserted: {task.task_id} (priority: {task.priority})")
print("\nExtracting tasks (lowest priority first):")
while not pq.is_empty():
task = pq.extract_min()
print(f" Extracted: {task.task_id} (priority: {task.priority})")
def demo_key_operations():
"""Demonstrate priority key update operations."""
print("\n" + "=" * 80)
print("PRIORITY KEY UPDATE OPERATIONS")
print("=" * 80)
pq = PriorityQueue(is_max_heap=True)
# Insert tasks
task1 = Task("T1", priority=10, arrival_time=0.0)
task2 = Task("T2", priority=20, arrival_time=1.0)
task3 = Task("T3", priority=15, arrival_time=2.0)
pq.insert(task1)
pq.insert(task2)
pq.insert(task3)
print("\nInitial state:")
print(f" Top task: {pq.peek().task_id} (priority: {pq.peek().priority})")
# Increase priority
print("\n1. Increasing T1's priority from 10 to 25:")
success = pq.increase_key(task1, 25)
print(f" Update successful: {success}")
print(f" New priority: {task1.priority}")
print(f" Top task: {pq.peek().task_id} (priority: {pq.peek().priority})")
# Decrease priority
print("\n2. Decreasing T1's priority from 25 to 12:")
success = pq.decrease_key(task1, 12)
print(f" Update successful: {success}")
print(f" New priority: {task1.priority}")
print(f" Top task: {pq.peek().task_id} (priority: {pq.peek().priority})")
def demo_task_scheduling():
"""Demonstrate task scheduling simulation."""
print("\n" + "=" * 80)
print("TASK SCHEDULING SIMULATION")
print("=" * 80)
pq = PriorityQueue(is_max_heap=True)
# Create tasks with deadlines
tasks = [
Task("T1", priority=10, arrival_time=0.0, deadline=100.0, execution_time=5.0),
Task("T2", priority=15, arrival_time=1.0, deadline=50.0, execution_time=3.0),
Task("T3", priority=8, arrival_time=2.0, deadline=200.0, execution_time=10.0),
Task("T4", priority=20, arrival_time=3.0, deadline=30.0, execution_time=2.0),
Task("T5", priority=12, arrival_time=4.0, deadline=150.0, execution_time=7.0)
]
print("\nTasks to schedule:")
for task in tasks:
print(f" {task.task_id}: priority={task.priority}, deadline={task.deadline}, "
f"execution_time={task.execution_time}")
# Insert all tasks
for task in tasks:
pq.insert(task)
print("\nScheduling order (by priority):")
current_time = 0.0
while not pq.is_empty():
task = pq.extract_max()
print(f"\n Executing: {task.task_id}")
print(f" Priority: {task.priority}")
print(f" Start time: {current_time}")
print(f" Execution time: {task.execution_time}")
print(f" Deadline: {task.deadline}")
# Check if task will meet deadline
completion_time = current_time + task.execution_time
if task.deadline and completion_time > task.deadline:
print(f" ⚠️ WARNING: Will miss deadline!")
else:
print(f" ✓ Will meet deadline")
current_time = completion_time
print(f"\n Total completion time: {current_time}")
def demo_large_queue():
"""Demonstrate performance with large queue."""
print("\n" + "=" * 80)
print("LARGE QUEUE PERFORMANCE")
print("=" * 80)
import time
pq = PriorityQueue(is_max_heap=True)
num_tasks = 10000
print(f"\nInserting {num_tasks} tasks...")
start = time.perf_counter()
for i in range(num_tasks):
priority = (i * 7) % 100 # Vary priorities
task = Task(f"T{i}", priority=priority, arrival_time=float(i))
pq.insert(task)
insert_time = time.perf_counter() - start
print(f" Insert time: {insert_time:.6f} seconds")
print(f" Queue size: {pq.size()}")
print(f"\nExtracting all tasks...")
start = time.perf_counter()
count = 0
prev_priority = float('inf')
while not pq.is_empty():
task = pq.extract_max()
# Verify ordering
assert task.priority <= prev_priority, "Ordering violated!"
prev_priority = task.priority
count += 1
extract_time = time.perf_counter() - start
print(f" Extract time: {extract_time:.6f} seconds")
print(f" Tasks extracted: {count}")
print(f" Ordering verified: ✓")
def main():
"""Run all demonstrations."""
print("\n" + "=" * 80)
print("PRIORITY QUEUE IMPLEMENTATION DEMONSTRATION")
print("Author: Carlos Gutierrez")
print("Email: cgutierrez44833@ucumberlands.edu")
print("=" * 80)
demo_basic_operations()
demo_min_heap()
demo_key_operations()
demo_task_scheduling()
demo_large_queue()
print("\n" + "=" * 80)
print("DEMONSTRATION COMPLETE")
print("=" * 80 + "\n")
if __name__ == "__main__":
main()

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#!/usr/bin/env python3
"""
Task Scheduler Simulation Demonstration
This script demonstrates the task scheduler implementation using the priority queue.
It shows various scheduling scenarios and analyzes the results.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import sys
import os
# Add parent directory to path
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from src.scheduler import TaskScheduler, simulate_scheduler
from src.task import Task
def demo_basic_scheduling():
"""Demonstrate basic priority-based scheduling."""
print("=" * 80)
print("BASIC PRIORITY-BASED SCHEDULING")
print("=" * 80)
scheduler = TaskScheduler()
# Create tasks with different priorities
tasks = [
Task("T1", priority=10, arrival_time=0.0, execution_time=5.0, description="Low priority task"),
Task("T2", priority=30, arrival_time=0.0, execution_time=3.0, description="High priority task"),
Task("T3", priority=20, arrival_time=0.0, execution_time=4.0, description="Medium priority task"),
Task("T4", priority=15, arrival_time=0.0, execution_time=2.0, description="Medium-low priority task"),
]
print("\nTasks to schedule (in priority order):")
for task in sorted(tasks, key=lambda t: t.priority, reverse=True):
print(f" {task.task_id}: priority={task.priority}, execution_time={task.execution_time}")
results = scheduler.schedule_tasks(tasks)
scheduler.print_schedule(results)
def demo_deadline_scheduling():
"""Demonstrate scheduling with deadlines."""
print("\n" + "=" * 80)
print("SCHEDULING WITH DEADLINES")
print("=" * 80)
scheduler = TaskScheduler()
# Create tasks with deadlines
tasks = [
Task("T1", priority=10, arrival_time=0.0, deadline=100.0, execution_time=5.0),
Task("T2", priority=20, arrival_time=0.0, deadline=30.0, execution_time=3.0),
Task("T3", priority=15, arrival_time=0.0, deadline=50.0, execution_time=10.0),
Task("T4", priority=25, arrival_time=0.0, deadline=20.0, execution_time=2.0),
Task("T5", priority=12, arrival_time=0.0, deadline=150.0, execution_time=7.0),
]
print("\nTasks with deadlines:")
for task in tasks:
print(f" {task.task_id}: priority={task.priority}, deadline={task.deadline}, "
f"execution_time={task.execution_time}")
results = scheduler.schedule_tasks(tasks)
scheduler.print_schedule(results)
def demo_large_workload():
"""Demonstrate scheduling a large number of tasks."""
print("\n" + "=" * 80)
print("LARGE WORKLOAD SCHEDULING")
print("=" * 80)
import random
# Generate random tasks
num_tasks = 50
tasks = []
random.seed(42) # For reproducibility
for i in range(num_tasks):
priority = random.randint(1, 100)
execution_time = random.uniform(0.5, 10.0)
deadline = random.uniform(10.0, 200.0)
tasks.append(
Task(f"T{i+1}", priority=priority, arrival_time=0.0,
deadline=deadline, execution_time=execution_time)
)
print(f"\nScheduling {num_tasks} tasks...")
stats = simulate_scheduler(tasks, verbose=False)
print(f"\nScheduling Statistics:")
print(f" Total tasks: {stats.total_tasks}")
print(f" Completed: {stats.completed_tasks}")
print(f" Deadline met: {stats.deadline_met} ({stats.deadline_met/stats.total_tasks*100:.1f}%)")
print(f" Deadline missed: {stats.deadline_missed} ({stats.deadline_missed/stats.total_tasks*100:.1f}%)")
print(f" Total execution time: {stats.total_execution_time:.2f}")
print(f" Average wait time: {stats.average_wait_time:.2f}")
print(f" Throughput: {stats.throughput:.2f} tasks/time unit")
def demo_priority_vs_deadline():
"""Compare priority-based vs deadline-based scheduling."""
print("\n" + "=" * 80)
print("PRIORITY-BASED vs DEADLINE-AWARE SCHEDULING")
print("=" * 80)
# Create tasks where high priority tasks have tight deadlines
tasks = [
Task("T1", priority=30, arrival_time=0.0, deadline=15.0, execution_time=10.0),
Task("T2", priority=20, arrival_time=0.0, deadline=50.0, execution_time=5.0),
Task("T3", priority=10, arrival_time=0.0, deadline=100.0, execution_time=3.0),
]
print("\nScenario: High priority task (T1) has tight deadline")
print("Tasks:")
for task in tasks:
print(f" {task.task_id}: priority={task.priority}, deadline={task.deadline}, "
f"execution_time={task.execution_time}")
# Priority-based scheduling
scheduler = TaskScheduler()
results = scheduler.schedule_tasks(tasks)
print("\nPriority-based scheduling (highest priority first):")
scheduler.print_schedule(results)
# Note: This demonstrates that pure priority scheduling may miss deadlines
# A more sophisticated scheduler could use deadline-aware priority adjustment
def main():
"""Run all scheduler demonstrations."""
print("\n" + "=" * 80)
print("TASK SCHEDULER SIMULATION DEMONSTRATION")
print("Author: Carlos Gutierrez")
print("Email: cgutierrez44833@ucumberlands.edu")
print("=" * 80)
demo_basic_scheduling()
demo_deadline_scheduling()
demo_large_workload()
demo_priority_vs_deadline()
print("\n" + "=" * 80)
print("DEMONSTRATION COMPLETE")
print("=" * 80)
print("\nKey Observations:")
print("1. Priority-based scheduling ensures high-priority tasks execute first")
print("2. Pure priority scheduling may miss deadlines for lower-priority tasks")
print("3. The scheduler efficiently handles large workloads using O(n log n) algorithm")
print("4. Statistics provide insights into scheduling performance")
print("=" * 80 + "\n")
if __name__ == "__main__":
main()

21
requirements.txt Normal file
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# MSCS532 Assignment 4: Heapsort and Priority Queue Implementation
# Python Dependencies
# Core functionality uses only Python standard library
# No external dependencies are required for basic usage
# Optional: For generating performance comparison plots
matplotlib>=3.5.0
numpy>=1.21.0
# Optional: For enhanced testing (if desired)
# pytest>=7.0.0
# pytest-cov>=4.0.0
# Optional: For performance profiling (if desired)
# cProfile (built-in)
# line_profiler>=4.0.0
# Note: Core functionality works with Python 3.7+ standard library only
# matplotlib and numpy are only needed for generating visualization plots

17
src/__init__.py Normal file
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"""
MSCS532 Assignment 4: Heapsort and Priority Queue Implementation
This package contains implementations of:
- Heapsort algorithm
- Priority Queue data structure
- Task scheduling simulation
- Performance comparison utilities
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
__version__ = "1.0.0"
__author__ = "Carlos Gutierrez"
__email__ = "cgutierrez44833@ucumberlands.edu"

243
src/comparison.py Normal file
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"""
Sorting Algorithm Comparison Module
This module provides utilities to empirically compare the performance of
Heapsort with other sorting algorithms (Quicksort and Merge Sort) on
different input sizes and distributions.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import time
import random
from typing import List, Callable, Dict, Tuple
from .heapsort import heapsort
def quicksort(arr: List[int], low: int = 0, high: int = None) -> List[int]:
"""
Quicksort implementation for comparison.
Time Complexity: O(n log n) average, O(n²) worst case
Args:
arr: Array to sort
low: Starting index
high: Ending index
Returns:
List[int]: Sorted array
"""
if high is None:
high = len(arr) - 1
arr = arr.copy()
# Use iterative approach to avoid recursion depth issues
stack = [(low, high)]
while stack:
low, high = stack.pop()
if low < high:
pi = _partition(arr, low, high)
# Push smaller partition first to reduce stack size
if pi - low < high - pi:
stack.append((pi + 1, high))
stack.append((low, pi - 1))
else:
stack.append((low, pi - 1))
stack.append((pi + 1, high))
return arr
def _partition(arr: List[int], low: int, high: int) -> int:
"""Partition function for Quicksort."""
pivot = arr[high]
i = low - 1
for j in range(low, high):
if arr[j] <= pivot:
i += 1
arr[i], arr[j] = arr[j], arr[i]
arr[i + 1], arr[high] = arr[high], arr[i + 1]
return i + 1
def merge_sort(arr: List[int]) -> List[int]:
"""
Merge Sort implementation for comparison.
Time Complexity: O(n log n) in all cases
Args:
arr: Array to sort
Returns:
List[int]: Sorted array
"""
if len(arr) <= 1:
return arr.copy()
mid = len(arr) // 2
left = merge_sort(arr[:mid])
right = merge_sort(arr[mid:])
return _merge(left, right)
def _merge(left: List[int], right: List[int]) -> List[int]:
"""Merge function for Merge Sort."""
result = []
i = j = 0
while i < len(left) and j < len(right):
if left[i] <= right[j]:
result.append(left[i])
i += 1
else:
result.append(right[j])
j += 1
result.extend(left[i:])
result.extend(right[j:])
return result
def generate_sorted_array(n: int) -> List[int]:
"""Generate a sorted array of size n."""
return list(range(n))
def generate_reverse_sorted_array(n: int) -> List[int]:
"""Generate a reverse-sorted array of size n."""
return list(range(n, 0, -1))
def generate_random_array(n: int, seed: int = None) -> List[int]:
"""Generate a random array of size n."""
if seed is not None:
random.seed(seed)
return [random.randint(1, n * 10) for _ in range(n)]
def measure_time(func: Callable, arr: List[int]) -> Tuple[float, List[int]]:
"""
Measure the execution time of a sorting function.
Args:
func: The sorting function to measure
arr: The array to sort
Returns:
Tuple[float, List[int]]: Execution time in seconds and sorted array
"""
start_time = time.perf_counter()
sorted_arr = func(arr)
end_time = time.perf_counter()
return end_time - start_time, sorted_arr
def compare_sorting_algorithms(
sizes: List[int],
distributions: Dict[str, Callable[[int], List[int]]] = None
) -> Dict[str, Dict[str, List[float]]]:
"""
Compare Heapsort, Quicksort, and Merge Sort on different input sizes and distributions.
Args:
sizes: List of input sizes to test
distributions: Dictionary mapping distribution names to generator functions
Returns:
Dictionary containing timing results for each algorithm and distribution
Examples:
>>> results = compare_sorting_algorithms([100, 1000, 10000])
>>> print(results['heapsort']['random'][0])
"""
if distributions is None:
distributions = {
'sorted': generate_sorted_array,
'reverse_sorted': generate_reverse_sorted_array,
'random': generate_random_array
}
algorithms = {
'heapsort': lambda arr: heapsort(arr.copy()),
'quicksort': quicksort,
'merge_sort': merge_sort
}
results = {
algo: {dist: [] for dist in distributions.keys()}
for algo in algorithms.keys()
}
for size in sizes:
print(f"Testing with size {size}...")
for dist_name, dist_func in distributions.items():
arr = dist_func(size)
for algo_name, algo_func in algorithms.items():
time_taken, _ = measure_time(algo_func, arr)
results[algo_name][dist_name].append(time_taken)
print(f" {algo_name} ({dist_name}): {time_taken:.6f}s")
return results
def print_comparison_results(results: Dict[str, Dict[str, List[float]]], sizes: List[int]) -> None:
"""
Print comparison results in a formatted table.
Args:
results: Results dictionary from compare_sorting_algorithms
sizes: List of input sizes that were tested
"""
print("\n" + "=" * 80)
print("SORTING ALGORITHM COMPARISON RESULTS")
print("=" * 80)
distributions = list(next(iter(results.values())).keys())
for dist in distributions:
print(f"\n{dist.upper().replace('_', ' ')} INPUT:")
print("-" * 80)
print(f"{'Size':<10} {'Heapsort':<15} {'Quicksort':<15} {'Merge Sort':<15}")
print("-" * 80)
for i, size in enumerate(sizes):
heapsort_time = results['heapsort'][dist][i]
quicksort_time = results['quicksort'][dist][i]
merge_sort_time = results['merge_sort'][dist][i]
print(f"{size:<10} {heapsort_time:<15.6f} {quicksort_time:<15.6f} {merge_sort_time:<15.6f}")
print("-" * 80)
def run_comparison(sizes: List[int] = None) -> Dict[str, Dict[str, List[float]]]:
"""
Run a complete comparison of sorting algorithms.
Args:
sizes: List of input sizes to test (default: [100, 1000, 10000, 100000])
Returns:
Dictionary containing timing results
"""
if sizes is None:
sizes = [100, 1000, 10000, 100000]
print("Starting sorting algorithm comparison...")
print(f"Testing sizes: {sizes}")
print()
results = compare_sorting_algorithms(sizes)
print_comparison_results(results, sizes)
return results

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"""
Heapsort Implementation
This module provides a complete implementation of the Heapsort algorithm
using a max-heap data structure. The implementation includes:
- Max-heap construction
- Heap property maintenance
- In-place sorting with O(n log n) time complexity
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
from typing import List, TypeVar, Callable
T = TypeVar('T')
def _heapify(arr: List[T], n: int, i: int, key: Callable[[T], T] = lambda x: x) -> None:
"""
Maintain the max-heap property for a subtree rooted at index i.
This function assumes that the subtrees rooted at left and right children
are already max-heaps, and ensures that the subtree rooted at i is also a max-heap.
Time Complexity: O(log n) where n is the size of the heap
Args:
arr: The array representing the heap
n: Size of the heap (may be smaller than len(arr))
i: Index of the root of the subtree to heapify
key: Optional function to extract comparison key from elements
Examples:
>>> arr = [4, 10, 3, 5, 1]
>>> _heapify(arr, 5, 0)
>>> arr
[10, 5, 3, 4, 1]
"""
largest = i # Initialize largest as root
left = 2 * i + 1 # Left child index
right = 2 * i + 2 # Right child index
# Compare root with left child
if left < n and key(arr[left]) > key(arr[largest]):
largest = left
# Compare largest with right child
if right < n and key(arr[right]) > key(arr[largest]):
largest = right
# If largest is not root, swap and continue heapifying
if largest != i:
arr[i], arr[largest] = arr[largest], arr[i]
_heapify(arr, n, largest, key)
def _build_max_heap(arr: List[T], key: Callable[[T], T] = lambda x: x) -> None:
"""
Build a max-heap from an unsorted array.
This function rearranges the array elements to satisfy the max-heap property.
It starts from the last non-leaf node and works backwards to the root.
Time Complexity: O(n) - linear time despite nested loops
Args:
arr: The array to convert into a max-heap
key: Optional function to extract comparison key from elements
Examples:
>>> arr = [4, 10, 3, 5, 1]
>>> _build_max_heap(arr)
>>> arr
[10, 5, 3, 4, 1]
"""
n = len(arr)
# Start from the last non-leaf node and work backwards
# Last non-leaf node is at index (n // 2) - 1
for i in range(n // 2 - 1, -1, -1):
_heapify(arr, n, i, key)
def heapsort(arr: List[T], key: Callable[[T], T] = lambda x: x, inplace: bool = True) -> List[T]:
"""
Sort an array using the Heapsort algorithm.
Heapsort is an in-place sorting algorithm with O(n log n) time complexity
in all cases (worst, average, and best). It works by:
1. Building a max-heap from the input array
2. Repeatedly extracting the maximum element and placing it at the end
3. Reducing the heap size and maintaining the heap property
Time Complexity: O(n log n) in all cases
Space Complexity: O(1) for in-place sorting, O(n) if not in-place
Args:
arr: The array to sort
key: Optional function to extract comparison key from elements
inplace: If True, sort in-place (modifies original array). If False, returns a new sorted array.
Returns:
List[T]: The sorted array (same reference if inplace=True, new list if inplace=False)
Examples:
>>> arr = [12, 11, 13, 5, 6, 7]
>>> heapsort(arr)
[5, 6, 7, 11, 12, 13]
>>> arr
[5, 6, 7, 11, 12, 13]
>>> arr = [3, 1, 4, 1, 5, 9, 2, 6]
>>> sorted_arr = heapsort(arr, inplace=False)
>>> sorted_arr
[1, 1, 2, 3, 4, 5, 6, 9]
>>> arr
[3, 1, 4, 1, 5, 9, 2, 6]
"""
if not arr:
return arr
# Create a copy if not sorting in-place
if not inplace:
arr = arr.copy()
n = len(arr)
# Step 1: Build max-heap
_build_max_heap(arr, key)
# Step 2: Extract elements one by one
for i in range(n - 1, 0, -1):
# Move current root (maximum) to end
arr[0], arr[i] = arr[i], arr[0]
# Reduce heap size and heapify the root
_heapify(arr, i, 0, key)
return arr
def heap_extract_max(arr: List[T], key: Callable[[T], T] = lambda x: x) -> T:
"""
Extract and return the maximum element from a max-heap.
This function removes the maximum element from the heap and maintains
the heap property. The heap is assumed to be a valid max-heap.
Time Complexity: O(log n)
Args:
arr: The max-heap array
key: Optional function to extract comparison key from elements
Returns:
T: The maximum element
Raises:
IndexError: If the heap is empty
Examples:
>>> heap = [10, 5, 3, 4, 1]
>>> max_val = heap_extract_max(heap)
>>> max_val
10
>>> heap
[5, 4, 3, 1]
"""
if not arr:
raise IndexError("Cannot extract from empty heap")
if len(arr) == 1:
return arr.pop()
# Store the maximum (root)
max_val = arr[0]
# Move last element to root
arr[0] = arr.pop()
# Heapify to maintain heap property
_heapify(arr, len(arr), 0, key)
return max_val
def heap_insert(arr: List[T], item: T, key: Callable[[T], T] = lambda x: x) -> None:
"""
Insert an element into a max-heap.
This function adds a new element to the heap and maintains the heap property
by bubbling up the element if necessary.
Time Complexity: O(log n)
Args:
arr: The max-heap array
item: The element to insert
key: Optional function to extract comparison key from elements
Examples:
>>> heap = [10, 5, 3, 4, 1]
>>> heap_insert(heap, 15)
>>> heap
[15, 10, 3, 4, 1, 5]
"""
arr.append(item)
i = len(arr) - 1
# Bubble up: compare with parent and swap if necessary
while i > 0:
parent = (i - 1) // 2
if key(arr[parent]) >= key(arr[i]):
break
arr[parent], arr[i] = arr[i], arr[parent]
i = parent

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"""
Priority Queue Implementation
This module implements a Priority Queue data structure using a binary heap.
The implementation supports both max-heap (highest priority first) and
min-heap (lowest priority first) configurations.
The priority queue is implemented using a Python list to represent the binary heap,
which provides efficient access to parent and child nodes through index calculations.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
from typing import List, Optional, TypeVar, Callable
from .task import Task
T = TypeVar('T')
class PriorityQueue:
"""
A Priority Queue implementation using a binary heap.
This class supports both max-heap and min-heap configurations. By default,
it uses a max-heap where higher priority values are extracted first.
The heap is implemented using a list, where for a node at index i:
- Parent is at index (i-1)//2
- Left child is at index 2*i+1
- Right child is at index 2*i+2
Attributes:
heap (List[T]): The list representing the binary heap
is_max_heap (bool): True for max-heap, False for min-heap
key (Callable): Function to extract priority/comparison key
Time Complexity Analysis:
- insert(): O(log n) - bubble up operation
- extract_max()/extract_min(): O(log n) - heapify operation
- increase_key()/decrease_key(): O(log n) - bubble up/down
- is_empty(): O(1) - constant time check
- peek(): O(1) - constant time access to root
Space Complexity: O(n) where n is the number of elements
Examples:
>>> pq = PriorityQueue()
>>> pq.insert(Task("T1", priority=10, arrival_time=0.0))
>>> pq.insert(Task("T2", priority=5, arrival_time=1.0))
>>> pq.insert(Task("T3", priority=15, arrival_time=2.0))
>>> task = pq.extract_max()
>>> task.task_id
'T3'
"""
def __init__(self, is_max_heap: bool = True, key: Optional[Callable[[T], int]] = None):
"""
Initialize an empty priority queue.
Args:
is_max_heap: If True, use max-heap (higher priority first).
If False, use min-heap (lower priority first).
key: Optional function to extract priority from elements.
If None, elements are compared directly.
Examples:
>>> pq = PriorityQueue(is_max_heap=True)
>>> pq.is_empty()
True
"""
self.heap: List[T] = []
self.is_max_heap = is_max_heap
self.key = key if key is not None else (lambda x: x.priority if isinstance(x, Task) else x)
def _compare(self, a: T, b: T) -> bool:
"""
Compare two elements based on heap type.
Args:
a: First element
b: Second element
Returns:
bool: True if a should be above b in the heap
"""
val_a = self.key(a)
val_b = self.key(b)
if self.is_max_heap:
return val_a > val_b
else:
return val_a < val_b
def _heapify_up(self, index: int) -> None:
"""
Maintain heap property by bubbling up an element.
Time Complexity: O(log n)
Args:
index: Index of the element to bubble up
"""
while index > 0:
parent = (index - 1) // 2
if self._compare(self.heap[index], self.heap[parent]):
self.heap[index], self.heap[parent] = self.heap[parent], self.heap[index]
index = parent
else:
break
def _heapify_down(self, index: int) -> None:
"""
Maintain heap property by bubbling down an element.
Time Complexity: O(log n)
Args:
index: Index of the element to bubble down
"""
n = len(self.heap)
while True:
largest_or_smallest = index
left = 2 * index + 1
right = 2 * index + 2
# Compare with left child
if left < n and self._compare(self.heap[left], self.heap[largest_or_smallest]):
largest_or_smallest = left
# Compare with right child
if right < n and self._compare(self.heap[right], self.heap[largest_or_smallest]):
largest_or_smallest = right
# If element is in correct position, stop
if largest_or_smallest == index:
break
# Swap and continue
self.heap[index], self.heap[largest_or_smallest] = \
self.heap[largest_or_smallest], self.heap[index]
index = largest_or_smallest
def insert(self, item: T) -> None:
"""
Insert an item into the priority queue.
The item is added to the end of the heap and then bubbled up
to maintain the heap property.
Time Complexity: O(log n) where n is the number of elements
Args:
item: The item to insert
Examples:
>>> pq = PriorityQueue()
>>> pq.insert(Task("T1", priority=10, arrival_time=0.0))
>>> pq.size()
1
"""
self.heap.append(item)
self._heapify_up(len(self.heap) - 1)
def extract_max(self) -> T:
"""
Extract and return the item with the highest priority (max-heap).
This operation removes the root of the heap, replaces it with the
last element, and maintains the heap property.
Time Complexity: O(log n)
Returns:
T: The item with the highest priority
Raises:
IndexError: If the priority queue is empty
Examples:
>>> pq = PriorityQueue()
>>> pq.insert(Task("T1", priority=10, arrival_time=0.0))
>>> pq.insert(Task("T2", priority=5, arrival_time=1.0))
>>> task = pq.extract_max()
>>> task.priority
10
"""
if self.is_empty():
raise IndexError("Cannot extract from empty priority queue")
if len(self.heap) == 1:
return self.heap.pop()
root = self.heap[0]
self.heap[0] = self.heap.pop()
self._heapify_down(0)
return root
def extract_min(self) -> T:
"""
Extract and return the item with the lowest priority (min-heap).
This operation removes the root of the heap, replaces it with the
last element, and maintains the heap property.
Time Complexity: O(log n)
Returns:
T: The item with the lowest priority
Raises:
IndexError: If the priority queue is empty
Examples:
>>> pq = PriorityQueue(is_max_heap=False)
>>> pq.insert(Task("T1", priority=10, arrival_time=0.0))
>>> pq.insert(Task("T2", priority=5, arrival_time=1.0))
>>> task = pq.extract_min()
>>> task.priority
5
"""
if self.is_empty():
raise IndexError("Cannot extract from empty priority queue")
if len(self.heap) == 1:
return self.heap.pop()
root = self.heap[0]
self.heap[0] = self.heap.pop()
self._heapify_down(0)
return root
def increase_key(self, item: T, new_priority: int) -> bool:
"""
Increase the priority of an existing item in the priority queue.
This operation finds the item, updates its priority, and bubbles it up
if necessary to maintain the heap property.
Time Complexity: O(n) to find the item + O(log n) to bubble up = O(n)
Note: This could be optimized to O(log n) with a hash map for O(1) lookup
Args:
item: The item whose priority should be increased
new_priority: The new priority value
Returns:
bool: True if the item was found and updated, False otherwise
Examples:
>>> pq = PriorityQueue()
>>> task = Task("T1", priority=10, arrival_time=0.0)
>>> pq.insert(task)
>>> pq.increase_key(task, 20)
True
>>> task.priority
20
"""
# Find the item in the heap
try:
index = self.heap.index(item)
except ValueError:
return False
# Update priority
if isinstance(item, Task):
item.update_priority(new_priority)
# Bubble up if necessary
self._heapify_up(index)
return True
def decrease_key(self, item: T, new_priority: int) -> bool:
"""
Decrease the priority of an existing item in the priority queue.
This operation finds the item, updates its priority, and bubbles it down
if necessary to maintain the heap property.
Time Complexity: O(n) to find the item + O(log n) to bubble down = O(n)
Note: This could be optimized to O(log n) with a hash map for O(1) lookup
Args:
item: The item whose priority should be decreased
new_priority: The new priority value
Returns:
bool: True if the item was found and updated, False otherwise
Examples:
>>> pq = PriorityQueue()
>>> task = Task("T1", priority=20, arrival_time=0.0)
>>> pq.insert(task)
>>> pq.decrease_key(task, 10)
True
>>> task.priority
10
"""
# Find the item in the heap
try:
index = self.heap.index(item)
except ValueError:
return False
# Update priority
if isinstance(item, Task):
item.update_priority(new_priority)
# Bubble down if necessary
self._heapify_down(index)
return True
def is_empty(self) -> bool:
"""
Check if the priority queue is empty.
Time Complexity: O(1)
Returns:
bool: True if the priority queue is empty, False otherwise
Examples:
>>> pq = PriorityQueue()
>>> pq.is_empty()
True
>>> pq.insert(Task("T1", priority=10, arrival_time=0.0))
>>> pq.is_empty()
False
"""
return len(self.heap) == 0
def size(self) -> int:
"""
Get the number of items in the priority queue.
Time Complexity: O(1)
Returns:
int: The number of items in the priority queue
Examples:
>>> pq = PriorityQueue()
>>> pq.size()
0
>>> pq.insert(Task("T1", priority=10, arrival_time=0.0))
>>> pq.size()
1
"""
return len(self.heap)
def peek(self) -> Optional[T]:
"""
Get the highest (or lowest) priority item without removing it.
Time Complexity: O(1)
Returns:
Optional[T]: The root item, or None if the queue is empty
Examples:
>>> pq = PriorityQueue()
>>> pq.insert(Task("T1", priority=10, arrival_time=0.0))
>>> task = pq.peek()
>>> task.task_id
'T1'
"""
if self.is_empty():
return None
return self.heap[0]
def __str__(self) -> str:
"""String representation of the priority queue."""
return f"PriorityQueue(size={self.size()}, is_max_heap={self.is_max_heap})"
def __repr__(self) -> str:
"""Detailed string representation."""
return self.__str__()

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"""
Task Scheduler Simulation
This module implements a task scheduler using the priority queue data structure.
The scheduler demonstrates how priority queues can be used for task scheduling
in operating systems, job queues, and other scheduling applications.
The scheduler supports:
- Priority-based scheduling (highest priority first)
- Deadline monitoring
- Execution time tracking
- Scheduling statistics and analysis
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
from typing import List, Dict, Optional
from dataclasses import dataclass
from .priority_queue import PriorityQueue
from .task import Task
@dataclass
class SchedulingResult:
"""
Represents the result of scheduling a task.
Attributes:
task_id (str): ID of the scheduled task
start_time (float): Time when task execution started
completion_time (float): Time when task execution completed
deadline_met (bool): Whether the task met its deadline
wait_time (float): Time the task waited before execution
"""
task_id: str
start_time: float
completion_time: float
deadline_met: bool
wait_time: float
@dataclass
class SchedulingStatistics:
"""
Statistics from a scheduling simulation.
Attributes:
total_tasks (int): Total number of tasks scheduled
completed_tasks (int): Number of tasks that completed
deadline_met (int): Number of tasks that met their deadlines
deadline_missed (int): Number of tasks that missed their deadlines
total_execution_time (float): Total time spent executing tasks
average_wait_time (float): Average wait time for all tasks
throughput (float): Tasks completed per unit time
"""
total_tasks: int
completed_tasks: int
deadline_met: int
deadline_missed: int
total_execution_time: float
average_wait_time: float
throughput: float
class TaskScheduler:
"""
A priority-based task scheduler using a priority queue.
This scheduler implements a priority-based scheduling algorithm where
tasks with higher priority are executed first. The scheduler maintains
a priority queue and executes tasks in priority order.
Time Complexity Analysis:
- schedule_tasks(): O(n log n) where n is the number of tasks
- Inserting n tasks: O(n log n)
- Extracting n tasks: O(n log n)
- Space Complexity: O(n) for the priority queue
Examples:
>>> scheduler = TaskScheduler()
>>> tasks = [
... Task("T1", priority=10, arrival_time=0.0, deadline=100.0, execution_time=5.0),
... Task("T2", priority=20, arrival_time=0.0, deadline=50.0, execution_time=3.0)
... ]
>>> results = scheduler.schedule_tasks(tasks)
>>> print(f"Scheduled {len(results)} tasks")
Scheduled 2 tasks
"""
def __init__(self):
"""Initialize an empty task scheduler."""
self.priority_queue = PriorityQueue(is_max_heap=True)
self.current_time = 0.0
def schedule_tasks(self, tasks: List[Task]) -> List[SchedulingResult]:
"""
Schedule and execute a list of tasks based on priority.
This method implements a priority-based scheduling algorithm:
1. All tasks are inserted into the priority queue
2. Tasks are extracted and executed in priority order
3. Execution times and deadlines are tracked
Time Complexity: O(n log n) where n is the number of tasks
- Inserting n tasks: O(n log n)
- Extracting n tasks: O(n log n)
Args:
tasks: List of tasks to schedule
Returns:
List[SchedulingResult]: Results of scheduling each task
Examples:
>>> scheduler = TaskScheduler()
>>> tasks = [
... Task("T1", priority=10, arrival_time=0.0, execution_time=5.0),
... Task("T2", priority=20, arrival_time=0.0, execution_time=3.0)
... ]
>>> results = scheduler.schedule_tasks(tasks)
>>> results[0].task_id
'T2'
"""
# Reset scheduler state
self.priority_queue = PriorityQueue(is_max_heap=True)
self.current_time = 0.0
results: List[SchedulingResult] = []
# Insert all tasks into priority queue
# Time Complexity: O(n log n) for n insertions
for task in tasks:
self.priority_queue.insert(task)
# Execute tasks in priority order
# Time Complexity: O(n log n) for n extractions
while not self.priority_queue.is_empty():
task = self.priority_queue.extract_max()
# Calculate scheduling metrics
start_time = self.current_time
wait_time = start_time - task.arrival_time
completion_time = start_time + task.execution_time
# Check if deadline is met
deadline_met = True
if task.deadline is not None:
deadline_met = completion_time <= task.deadline
# Create result
result = SchedulingResult(
task_id=task.task_id,
start_time=start_time,
completion_time=completion_time,
deadline_met=deadline_met,
wait_time=wait_time
)
results.append(result)
# Update current time
self.current_time = completion_time
return results
def get_statistics(self, results: List[SchedulingResult]) -> SchedulingStatistics:
"""
Calculate scheduling statistics from results.
Time Complexity: O(n) where n is the number of results
Args:
results: List of scheduling results
Returns:
SchedulingStatistics: Calculated statistics
"""
if not results:
return SchedulingStatistics(
total_tasks=0,
completed_tasks=0,
deadline_met=0,
deadline_missed=0,
total_execution_time=0.0,
average_wait_time=0.0,
throughput=0.0
)
total_tasks = len(results)
completed_tasks = len(results)
deadline_met = sum(1 for r in results if r.deadline_met)
deadline_missed = total_tasks - deadline_met
total_execution_time = max(r.completion_time for r in results) if results else 0.0
average_wait_time = sum(r.wait_time for r in results) / total_tasks if total_tasks > 0 else 0.0
throughput = completed_tasks / total_execution_time if total_execution_time > 0 else 0.0
return SchedulingStatistics(
total_tasks=total_tasks,
completed_tasks=completed_tasks,
deadline_met=deadline_met,
deadline_missed=deadline_missed,
total_execution_time=total_execution_time,
average_wait_time=average_wait_time,
throughput=throughput
)
def print_schedule(self, results: List[SchedulingResult]) -> None:
"""
Print a formatted schedule of task execution.
Args:
results: List of scheduling results to display
"""
print("\n" + "=" * 80)
print("TASK SCHEDULING RESULTS")
print("=" * 80)
print(f"{'Task ID':<10} {'Start':<12} {'Completion':<12} {'Wait':<12} {'Deadline':<10}")
print("-" * 80)
for result in results:
deadline_status = "✓ Met" if result.deadline_met else "✗ Missed"
print(f"{result.task_id:<10} {result.start_time:<12.2f} "
f"{result.completion_time:<12.2f} {result.wait_time:<12.2f} {deadline_status:<10}")
print("-" * 80)
# Print statistics
stats = self.get_statistics(results)
print(f"\nStatistics:")
print(f" Total tasks: {stats.total_tasks}")
print(f" Completed: {stats.completed_tasks}")
print(f" Deadline met: {stats.deadline_met}")
print(f" Deadline missed: {stats.deadline_missed}")
print(f" Total execution time: {stats.total_execution_time:.2f}")
print(f" Average wait time: {stats.average_wait_time:.2f}")
print(f" Throughput: {stats.throughput:.2f} tasks/time unit")
print("=" * 80)
def simulate_scheduler(tasks: List[Task], verbose: bool = True) -> SchedulingStatistics:
"""
Simulate a task scheduler with the given tasks.
This is a convenience function that creates a scheduler, schedules tasks,
and returns statistics.
Time Complexity: O(n log n) where n is the number of tasks
Args:
tasks: List of tasks to schedule
verbose: If True, print the schedule
Returns:
SchedulingStatistics: Statistics from the simulation
Examples:
>>> tasks = [
... Task("T1", priority=10, arrival_time=0.0, deadline=100.0, execution_time=5.0),
... Task("T2", priority=20, arrival_time=0.0, deadline=50.0, execution_time=3.0)
... ]
>>> stats = simulate_scheduler(tasks, verbose=False)
>>> stats.total_tasks
2
"""
scheduler = TaskScheduler()
results = scheduler.schedule_tasks(tasks)
if verbose:
scheduler.print_schedule(results)
return scheduler.get_statistics(results)

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"""
Task Module
This module defines the Task class used to represent individual tasks
in the priority queue implementation. Each task contains information
such as task ID, priority, arrival time, and deadline.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
from dataclasses import dataclass
from typing import Optional
@dataclass
class Task:
"""
Represents a task with priority, timing, and identification information.
Attributes:
task_id (str): Unique identifier for the task
priority (int): Priority level (higher values = higher priority)
arrival_time (float): Time when the task arrives in the system
deadline (Optional[float]): Deadline for task completion (None if no deadline)
execution_time (float): Estimated time required to execute the task
description (str): Optional description of the task
Examples:
>>> task = Task("T1", priority=10, arrival_time=0.0, deadline=100.0)
>>> print(task)
Task(task_id='T1', priority=10, arrival_time=0.0, deadline=100.0, execution_time=1.0, description='')
"""
task_id: str
priority: int
arrival_time: float
deadline: Optional[float] = None
execution_time: float = 1.0
description: str = ""
def __lt__(self, other: 'Task') -> bool:
"""
Compare tasks by priority (for min-heap: lower priority first).
Args:
other: Another Task object to compare with
Returns:
bool: True if this task has lower priority than other
"""
return self.priority < other.priority
def __gt__(self, other: 'Task') -> bool:
"""
Compare tasks by priority (for max-heap: higher priority first).
Args:
other: Another Task object to compare with
Returns:
bool: True if this task has higher priority than other
"""
return self.priority > other.priority
def __eq__(self, other: 'Task') -> bool:
"""
Check if two tasks have the same priority.
Args:
other: Another Task object to compare with
Returns:
bool: True if tasks have the same priority
"""
if not isinstance(other, Task):
return False
return self.priority == other.priority
def __le__(self, other: 'Task') -> bool:
"""Less than or equal comparison."""
return self.priority <= other.priority
def __ge__(self, other: 'Task') -> bool:
"""Greater than or equal comparison."""
return self.priority >= other.priority
def update_priority(self, new_priority: int) -> None:
"""
Update the priority of the task.
Args:
new_priority: The new priority value
"""
self.priority = new_priority
def is_overdue(self, current_time: float) -> bool:
"""
Check if the task has passed its deadline.
Args:
current_time: The current time in the system
Returns:
bool: True if deadline exists and has passed
"""
if self.deadline is None:
return False
return current_time > self.deadline
def time_until_deadline(self, current_time: float) -> Optional[float]:
"""
Calculate the time remaining until the deadline.
Args:
current_time: The current time in the system
Returns:
Optional[float]: Time remaining until deadline, or None if no deadline
"""
if self.deadline is None:
return None
return max(0.0, self.deadline - current_time)

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"""
Test Suite for MSCS532 Assignment 4
This package contains comprehensive tests for:
- Heapsort implementation
- Priority Queue implementation
- Task class
- Sorting algorithm comparisons
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""

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"""
Test Suite for Sorting Algorithm Comparison
This module contains tests for the comparison utilities and sorting algorithms.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import unittest
import sys
import os
# Add parent directory to path to import src modules
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from src.comparison import (
quicksort, merge_sort,
generate_sorted_array, generate_reverse_sorted_array, generate_random_array
)
class TestSortingAlgorithms(unittest.TestCase):
"""Test cases for sorting algorithm implementations."""
def test_quicksort_empty(self):
"""Test quicksort on empty array."""
arr = []
result = quicksort(arr)
self.assertEqual(result, [])
def test_quicksort_single(self):
"""Test quicksort on single element."""
arr = [42]
result = quicksort(arr)
self.assertEqual(result, [42])
def test_quicksort_sorted(self):
"""Test quicksort on sorted array."""
arr = [1, 2, 3, 4, 5]
result = quicksort(arr)
self.assertEqual(result, [1, 2, 3, 4, 5])
def test_quicksort_reverse(self):
"""Test quicksort on reverse-sorted array."""
arr = [5, 4, 3, 2, 1]
result = quicksort(arr)
self.assertEqual(result, [1, 2, 3, 4, 5])
def test_quicksort_random(self):
"""Test quicksort on random array."""
arr = [3, 1, 4, 1, 5, 9, 2, 6]
result = quicksort(arr)
self.assertEqual(result, [1, 1, 2, 3, 4, 5, 6, 9])
def test_merge_sort_empty(self):
"""Test merge sort on empty array."""
arr = []
result = merge_sort(arr)
self.assertEqual(result, [])
def test_merge_sort_single(self):
"""Test merge sort on single element."""
arr = [42]
result = merge_sort(arr)
self.assertEqual(result, [42])
def test_merge_sort_sorted(self):
"""Test merge sort on sorted array."""
arr = [1, 2, 3, 4, 5]
result = merge_sort(arr)
self.assertEqual(result, [1, 2, 3, 4, 5])
def test_merge_sort_reverse(self):
"""Test merge sort on reverse-sorted array."""
arr = [5, 4, 3, 2, 1]
result = merge_sort(arr)
self.assertEqual(result, [1, 2, 3, 4, 5])
def test_merge_sort_random(self):
"""Test merge sort on random array."""
arr = [3, 1, 4, 1, 5, 9, 2, 6]
result = merge_sort(arr)
self.assertEqual(result, [1, 1, 2, 3, 4, 5, 6, 9])
class TestArrayGenerators(unittest.TestCase):
"""Test cases for array generator functions."""
def test_generate_sorted_array(self):
"""Test generating sorted array."""
arr = generate_sorted_array(5)
self.assertEqual(arr, [0, 1, 2, 3, 4])
self.assertEqual(len(arr), 5)
def test_generate_reverse_sorted_array(self):
"""Test generating reverse-sorted array."""
arr = generate_reverse_sorted_array(5)
self.assertEqual(arr, [5, 4, 3, 2, 1])
self.assertEqual(len(arr), 5)
def test_generate_random_array(self):
"""Test generating random array."""
arr = generate_random_array(10, seed=42)
self.assertEqual(len(arr), 10)
# With same seed, should get same array
arr2 = generate_random_array(10, seed=42)
self.assertEqual(arr, arr2)
def test_generate_random_array_different_seeds(self):
"""Test that different seeds produce different arrays."""
arr1 = generate_random_array(100, seed=1)
arr2 = generate_random_array(100, seed=2)
# Very unlikely to be the same
self.assertNotEqual(arr1, arr2)
if __name__ == '__main__':
unittest.main()

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"""
Test Suite for Heapsort Implementation
This module contains comprehensive tests for the heapsort algorithm,
including edge cases, different data types, and correctness verification.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import unittest
import sys
import os
# Add parent directory to path to import src modules
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from src.heapsort import heapsort, heap_extract_max, heap_insert, _build_max_heap, _heapify
class TestHeapsort(unittest.TestCase):
"""Test cases for heapsort function."""
def test_empty_array(self):
"""Test sorting an empty array."""
arr = []
result = heapsort(arr)
self.assertEqual(result, [])
def test_single_element(self):
"""Test sorting an array with a single element."""
arr = [42]
result = heapsort(arr)
self.assertEqual(result, [42])
def test_already_sorted(self):
"""Test sorting an already sorted array."""
arr = [1, 2, 3, 4, 5]
result = heapsort(arr)
self.assertEqual(result, [1, 2, 3, 4, 5])
def test_reverse_sorted(self):
"""Test sorting a reverse-sorted array."""
arr = [5, 4, 3, 2, 1]
result = heapsort(arr)
self.assertEqual(result, [1, 2, 3, 4, 5])
def test_random_array(self):
"""Test sorting a random array."""
arr = [12, 11, 13, 5, 6, 7]
result = heapsort(arr)
self.assertEqual(result, [5, 6, 7, 11, 12, 13])
def test_duplicate_elements(self):
"""Test sorting an array with duplicate elements."""
arr = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5]
result = heapsort(arr)
self.assertEqual(result, [1, 1, 2, 3, 3, 4, 5, 5, 5, 6, 9])
def test_negative_numbers(self):
"""Test sorting an array with negative numbers."""
arr = [-5, -2, -8, 1, 3, -1]
result = heapsort(arr)
self.assertEqual(result, [-8, -5, -2, -1, 1, 3])
def test_large_array(self):
"""Test sorting a large array."""
arr = list(range(1000, 0, -1))
result = heapsort(arr)
self.assertEqual(result, list(range(1, 1001)))
def test_inplace_sorting(self):
"""Test that inplace sorting modifies the original array."""
arr = [3, 1, 4, 1, 5]
original_id = id(arr)
result = heapsort(arr, inplace=True)
self.assertEqual(id(result), original_id)
self.assertEqual(arr, [1, 1, 3, 4, 5])
def test_not_inplace_sorting(self):
"""Test that non-inplace sorting doesn't modify the original array."""
arr = [3, 1, 4, 1, 5]
original_arr = arr.copy()
result = heapsort(arr, inplace=False)
self.assertNotEqual(id(result), id(arr))
self.assertEqual(arr, original_arr)
self.assertEqual(result, [1, 1, 3, 4, 5])
def test_custom_key_function(self):
"""Test sorting with a custom key function."""
arr = [{'value': 3}, {'value': 1}, {'value': 4}]
result = heapsort(arr, key=lambda x: x['value'], inplace=False)
self.assertEqual([x['value'] for x in result], [1, 3, 4])
class TestHeapOperations(unittest.TestCase):
"""Test cases for heap utility functions."""
def test_heapify(self):
"""Test the heapify function."""
arr = [4, 10, 3, 5, 1]
_heapify(arr, 5, 0)
# After heapify, root should be the maximum
self.assertEqual(arr[0], 10)
def test_build_max_heap(self):
"""Test building a max-heap from an array."""
arr = [4, 10, 3, 5, 1]
_build_max_heap(arr)
# Root should be maximum
self.assertEqual(arr[0], 10)
# Verify heap property: parent >= children
for i in range(len(arr)):
left = 2 * i + 1
right = 2 * i + 2
if left < len(arr):
self.assertGreaterEqual(arr[i], arr[left])
if right < len(arr):
self.assertGreaterEqual(arr[i], arr[right])
def test_heap_extract_max(self):
"""Test extracting maximum from a heap."""
heap = [10, 5, 3, 4, 1]
_build_max_heap(heap)
max_val = heap_extract_max(heap)
self.assertEqual(max_val, 10)
self.assertEqual(len(heap), 4)
# Verify heap property is maintained
self.assertEqual(heap[0], 5)
def test_heap_extract_max_empty(self):
"""Test extracting from an empty heap raises error."""
heap = []
with self.assertRaises(IndexError):
heap_extract_max(heap)
def test_heap_insert(self):
"""Test inserting into a heap."""
heap = [10, 5, 3, 4, 1]
_build_max_heap(heap)
heap_insert(heap, 15)
# New maximum should be at root
self.assertEqual(heap[0], 15)
# Verify heap property
for i in range(len(heap)):
left = 2 * i + 1
right = 2 * i + 2
if left < len(heap):
self.assertGreaterEqual(heap[i], heap[left])
if right < len(heap):
self.assertGreaterEqual(heap[i], heap[right])
if __name__ == '__main__':
unittest.main()

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"""
Test Suite for Priority Queue Implementation
This module contains comprehensive tests for the Priority Queue data structure,
including all core operations and edge cases.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import unittest
import sys
import os
# Add parent directory to path to import src modules
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from src.priority_queue import PriorityQueue
from src.task import Task
class TestPriorityQueue(unittest.TestCase):
"""Test cases for Priority Queue implementation."""
def setUp(self):
"""Set up test fixtures."""
self.pq = PriorityQueue(is_max_heap=True)
def test_initialization(self):
"""Test priority queue initialization."""
pq = PriorityQueue()
self.assertTrue(pq.is_empty())
self.assertEqual(pq.size(), 0)
self.assertTrue(pq.is_max_heap)
def test_initialization_min_heap(self):
"""Test min-heap initialization."""
pq = PriorityQueue(is_max_heap=False)
self.assertTrue(pq.is_empty())
self.assertFalse(pq.is_max_heap)
def test_insert_single_task(self):
"""Test inserting a single task."""
task = Task("T1", priority=10, arrival_time=0.0)
self.pq.insert(task)
self.assertFalse(self.pq.is_empty())
self.assertEqual(self.pq.size(), 1)
def test_insert_multiple_tasks(self):
"""Test inserting multiple tasks."""
tasks = [
Task("T1", priority=10, arrival_time=0.0),
Task("T2", priority=5, arrival_time=1.0),
Task("T3", priority=15, arrival_time=2.0)
]
for task in tasks:
self.pq.insert(task)
self.assertEqual(self.pq.size(), 3)
def test_extract_max_ordering(self):
"""Test that extract_max returns tasks in priority order."""
tasks = [
Task("T1", priority=10, arrival_time=0.0),
Task("T2", priority=5, arrival_time=1.0),
Task("T3", priority=15, arrival_time=2.0),
Task("T4", priority=20, arrival_time=3.0)
]
for task in tasks:
self.pq.insert(task)
# Should extract in descending priority order
self.assertEqual(self.pq.extract_max().priority, 20)
self.assertEqual(self.pq.extract_max().priority, 15)
self.assertEqual(self.pq.extract_max().priority, 10)
self.assertEqual(self.pq.extract_max().priority, 5)
self.assertTrue(self.pq.is_empty())
def test_extract_max_empty(self):
"""Test extracting from empty queue raises error."""
with self.assertRaises(IndexError):
self.pq.extract_max()
def test_extract_min_ordering(self):
"""Test that extract_min returns tasks in ascending priority order."""
pq = PriorityQueue(is_max_heap=False)
tasks = [
Task("T1", priority=10, arrival_time=0.0),
Task("T2", priority=5, arrival_time=1.0),
Task("T3", priority=15, arrival_time=2.0),
Task("T4", priority=20, arrival_time=3.0)
]
for task in tasks:
pq.insert(task)
# Should extract in ascending priority order
self.assertEqual(pq.extract_min().priority, 5)
self.assertEqual(pq.extract_min().priority, 10)
self.assertEqual(pq.extract_min().priority, 15)
self.assertEqual(pq.extract_min().priority, 20)
self.assertTrue(pq.is_empty())
def test_peek(self):
"""Test peeking at the highest priority task."""
tasks = [
Task("T1", priority=10, arrival_time=0.0),
Task("T2", priority=5, arrival_time=1.0),
Task("T3", priority=15, arrival_time=2.0)
]
for task in tasks:
self.pq.insert(task)
peeked = self.pq.peek()
self.assertEqual(peeked.priority, 15)
# Peek should not remove the element
self.assertEqual(self.pq.size(), 3)
def test_peek_empty(self):
"""Test peeking at empty queue returns None."""
self.assertIsNone(self.pq.peek())
def test_increase_key(self):
"""Test increasing the priority of a task."""
task = Task("T1", priority=10, arrival_time=0.0)
self.pq.insert(task)
self.pq.insert(Task("T2", priority=20, arrival_time=1.0))
# Initially, T2 should be at root
self.assertEqual(self.pq.peek().priority, 20)
# Increase T1's priority
success = self.pq.increase_key(task, 25)
self.assertTrue(success)
self.assertEqual(task.priority, 25)
# Now T1 should be at root
self.assertEqual(self.pq.peek().priority, 25)
self.assertEqual(self.pq.peek().task_id, "T1")
def test_increase_key_not_found(self):
"""Test increasing key of non-existent task."""
task = Task("T1", priority=10, arrival_time=0.0)
success = self.pq.increase_key(task, 20)
self.assertFalse(success)
def test_decrease_key(self):
"""Test decreasing the priority of a task."""
task = Task("T1", priority=20, arrival_time=0.0)
self.pq.insert(task)
self.pq.insert(Task("T2", priority=10, arrival_time=1.0))
# Initially, T1 should be at root
self.assertEqual(self.pq.peek().priority, 20)
# Decrease T1's priority
success = self.pq.decrease_key(task, 5)
self.assertTrue(success)
self.assertEqual(task.priority, 5)
# Now T2 should be at root
self.assertEqual(self.pq.peek().priority, 10)
self.assertEqual(self.pq.peek().task_id, "T2")
def test_decrease_key_not_found(self):
"""Test decreasing key of non-existent task."""
task = Task("T1", priority=10, arrival_time=0.0)
success = self.pq.decrease_key(task, 5)
self.assertFalse(success)
def test_is_empty(self):
"""Test is_empty method."""
self.assertTrue(self.pq.is_empty())
self.pq.insert(Task("T1", priority=10, arrival_time=0.0))
self.assertFalse(self.pq.is_empty())
self.pq.extract_max()
self.assertTrue(self.pq.is_empty())
def test_size(self):
"""Test size method."""
self.assertEqual(self.pq.size(), 0)
for i in range(5):
self.pq.insert(Task(f"T{i}", priority=i, arrival_time=float(i)))
self.assertEqual(self.pq.size(), i + 1)
for i in range(5):
self.pq.extract_max()
self.assertEqual(self.pq.size(), 4 - i)
def test_large_queue(self):
"""Test priority queue with many elements."""
for i in range(1000):
self.pq.insert(Task(f"T{i}", priority=i, arrival_time=float(i)))
self.assertEqual(self.pq.size(), 1000)
# Extract all and verify ordering
prev_priority = float('inf')
while not self.pq.is_empty():
task = self.pq.extract_max()
self.assertLessEqual(task.priority, prev_priority)
prev_priority = task.priority
def test_duplicate_priorities(self):
"""Test handling of tasks with duplicate priorities."""
tasks = [
Task("T1", priority=10, arrival_time=0.0),
Task("T2", priority=10, arrival_time=1.0),
Task("T3", priority=10, arrival_time=2.0)
]
for task in tasks:
self.pq.insert(task)
# All should be extractable
extracted = []
while not self.pq.is_empty():
extracted.append(self.pq.extract_max())
self.assertEqual(len(extracted), 3)
self.assertTrue(all(task.priority == 10 for task in extracted))
if __name__ == '__main__':
unittest.main()

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"""
Test Suite for Task Scheduler Implementation
This module contains comprehensive tests for the task scheduler,
including scheduling algorithms, statistics, and edge cases.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import unittest
import sys
import os
# Add parent directory to path to import src modules
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from src.scheduler import TaskScheduler, SchedulingResult, SchedulingStatistics, simulate_scheduler
from src.task import Task
class TestTaskScheduler(unittest.TestCase):
"""Test cases for TaskScheduler class."""
def setUp(self):
"""Set up test fixtures."""
self.scheduler = TaskScheduler()
def test_basic_scheduling(self):
"""Test basic priority-based scheduling."""
tasks = [
Task("T1", priority=10, arrival_time=0.0, execution_time=5.0),
Task("T2", priority=20, arrival_time=0.0, execution_time=3.0),
Task("T3", priority=15, arrival_time=0.0, execution_time=4.0),
]
results = self.scheduler.schedule_tasks(tasks)
self.assertEqual(len(results), 3)
# Highest priority should execute first
self.assertEqual(results[0].task_id, "T2")
self.assertEqual(results[1].task_id, "T3")
self.assertEqual(results[2].task_id, "T1")
def test_scheduling_order(self):
"""Test that tasks are scheduled in priority order."""
tasks = [
Task("T1", priority=5, arrival_time=0.0, execution_time=1.0),
Task("T2", priority=10, arrival_time=0.0, execution_time=1.0),
Task("T3", priority=15, arrival_time=0.0, execution_time=1.0),
]
results = self.scheduler.schedule_tasks(tasks)
# Should be in descending priority order
priorities = [t.priority for t in tasks]
priorities.sort(reverse=True)
for i, result in enumerate(results):
# Find the task that matches this result
task = next(t for t in tasks if t.task_id == result.task_id)
self.assertEqual(task.priority, priorities[i])
def test_deadline_tracking(self):
"""Test that deadlines are correctly tracked."""
tasks = [
Task("T1", priority=20, arrival_time=0.0, deadline=10.0, execution_time=5.0),
Task("T2", priority=10, arrival_time=0.0, deadline=100.0, execution_time=20.0),
]
results = self.scheduler.schedule_tasks(tasks)
# T1 should meet deadline (starts at 0, completes at 5, deadline 10)
self.assertTrue(results[0].deadline_met)
# T2 should also meet deadline (starts at 5, completes at 25, deadline 100)
self.assertTrue(results[1].deadline_met)
def test_deadline_missed(self):
"""Test detection of missed deadlines."""
tasks = [
Task("T1", priority=20, arrival_time=0.0, deadline=3.0, execution_time=5.0),
]
results = self.scheduler.schedule_tasks(tasks)
# Task should miss deadline (completes at 5, deadline is 3)
self.assertFalse(results[0].deadline_met)
def test_wait_time_calculation(self):
"""Test wait time calculation."""
tasks = [
Task("T1", priority=20, arrival_time=0.0, execution_time=5.0),
Task("T2", priority=10, arrival_time=0.0, execution_time=3.0),
]
results = self.scheduler.schedule_tasks(tasks)
# T1 should have no wait time (executes first)
self.assertEqual(results[0].wait_time, 0.0)
# T2 should wait for T1 to complete
self.assertEqual(results[1].wait_time, 5.0)
def test_empty_task_list(self):
"""Test scheduling with empty task list."""
results = self.scheduler.schedule_tasks([])
self.assertEqual(len(results), 0)
def test_single_task(self):
"""Test scheduling a single task."""
tasks = [Task("T1", priority=10, arrival_time=0.0, execution_time=5.0)]
results = self.scheduler.schedule_tasks(tasks)
self.assertEqual(len(results), 1)
self.assertEqual(results[0].task_id, "T1")
self.assertEqual(results[0].start_time, 0.0)
self.assertEqual(results[0].completion_time, 5.0)
self.assertEqual(results[0].wait_time, 0.0)
class TestSchedulingStatistics(unittest.TestCase):
"""Test cases for scheduling statistics."""
def test_statistics_calculation(self):
"""Test statistics calculation."""
scheduler = TaskScheduler()
tasks = [
Task("T1", priority=20, arrival_time=0.0, deadline=10.0, execution_time=5.0),
Task("T2", priority=10, arrival_time=0.0, deadline=100.0, execution_time=3.0),
]
results = scheduler.schedule_tasks(tasks)
stats = scheduler.get_statistics(results)
self.assertEqual(stats.total_tasks, 2)
self.assertEqual(stats.completed_tasks, 2)
self.assertEqual(stats.deadline_met, 2)
self.assertEqual(stats.deadline_missed, 0)
self.assertEqual(stats.total_execution_time, 8.0) # 5 + 3
self.assertGreater(stats.average_wait_time, 0)
self.assertGreater(stats.throughput, 0)
def test_statistics_with_missed_deadlines(self):
"""Test statistics with missed deadlines."""
scheduler = TaskScheduler()
tasks = [
Task("T1", priority=20, arrival_time=0.0, deadline=3.0, execution_time=5.0),
Task("T2", priority=10, arrival_time=0.0, deadline=100.0, execution_time=3.0),
]
results = scheduler.schedule_tasks(tasks)
stats = scheduler.get_statistics(results)
self.assertEqual(stats.deadline_met, 1)
self.assertEqual(stats.deadline_missed, 1)
def test_statistics_empty_results(self):
"""Test statistics with empty results."""
scheduler = TaskScheduler()
stats = scheduler.get_statistics([])
self.assertEqual(stats.total_tasks, 0)
self.assertEqual(stats.completed_tasks, 0)
self.assertEqual(stats.total_execution_time, 0.0)
self.assertEqual(stats.average_wait_time, 0.0)
self.assertEqual(stats.throughput, 0.0)
class TestSimulateScheduler(unittest.TestCase):
"""Test cases for simulate_scheduler convenience function."""
def test_simulate_scheduler(self):
"""Test the simulate_scheduler function."""
tasks = [
Task("T1", priority=20, arrival_time=0.0, execution_time=5.0),
Task("T2", priority=10, arrival_time=0.0, execution_time=3.0),
]
stats = simulate_scheduler(tasks, verbose=False)
self.assertEqual(stats.total_tasks, 2)
self.assertEqual(stats.completed_tasks, 2)
if __name__ == '__main__':
unittest.main()

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tests/test_task.py Normal file
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"""
Test Suite for Task Class
This module contains tests for the Task class, including comparisons,
priority updates, and deadline checking.
Author: Carlos Gutierrez
Email: cgutierrez44833@ucumberlands.edu
"""
import unittest
import sys
import os
# Add parent directory to path to import src modules
sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
from src.task import Task
class TestTask(unittest.TestCase):
"""Test cases for Task class."""
def test_task_creation(self):
"""Test creating a task with all parameters."""
task = Task(
task_id="T1",
priority=10,
arrival_time=0.0,
deadline=100.0,
execution_time=5.0,
description="Test task"
)
self.assertEqual(task.task_id, "T1")
self.assertEqual(task.priority, 10)
self.assertEqual(task.arrival_time, 0.0)
self.assertEqual(task.deadline, 100.0)
self.assertEqual(task.execution_time, 5.0)
self.assertEqual(task.description, "Test task")
def test_task_creation_minimal(self):
"""Test creating a task with minimal parameters."""
task = Task("T1", priority=10, arrival_time=0.0)
self.assertEqual(task.task_id, "T1")
self.assertEqual(task.priority, 10)
self.assertEqual(task.arrival_time, 0.0)
self.assertIsNone(task.deadline)
self.assertEqual(task.execution_time, 1.0)
self.assertEqual(task.description, "")
def test_task_comparison_lt(self):
"""Test less than comparison."""
task1 = Task("T1", priority=5, arrival_time=0.0)
task2 = Task("T2", priority=10, arrival_time=1.0)
self.assertTrue(task1 < task2)
self.assertFalse(task2 < task1)
def test_task_comparison_gt(self):
"""Test greater than comparison."""
task1 = Task("T1", priority=10, arrival_time=0.0)
task2 = Task("T2", priority=5, arrival_time=1.0)
self.assertTrue(task1 > task2)
self.assertFalse(task2 > task1)
def test_task_comparison_eq(self):
"""Test equality comparison."""
task1 = Task("T1", priority=10, arrival_time=0.0)
task2 = Task("T2", priority=10, arrival_time=1.0)
task3 = Task("T3", priority=5, arrival_time=2.0)
self.assertTrue(task1 == task2)
self.assertFalse(task1 == task3)
def test_task_comparison_le(self):
"""Test less than or equal comparison."""
task1 = Task("T1", priority=5, arrival_time=0.0)
task2 = Task("T2", priority=10, arrival_time=1.0)
task3 = Task("T3", priority=5, arrival_time=2.0)
self.assertTrue(task1 <= task2)
self.assertTrue(task1 <= task3)
self.assertFalse(task2 <= task1)
def test_task_comparison_ge(self):
"""Test greater than or equal comparison."""
task1 = Task("T1", priority=10, arrival_time=0.0)
task2 = Task("T2", priority=5, arrival_time=1.0)
task3 = Task("T3", priority=10, arrival_time=2.0)
self.assertTrue(task1 >= task2)
self.assertTrue(task1 >= task3)
self.assertFalse(task2 >= task1)
def test_update_priority(self):
"""Test updating task priority."""
task = Task("T1", priority=10, arrival_time=0.0)
self.assertEqual(task.priority, 10)
task.update_priority(20)
self.assertEqual(task.priority, 20)
def test_is_overdue_with_deadline(self):
"""Test checking if task is overdue."""
task = Task("T1", priority=10, arrival_time=0.0, deadline=100.0)
self.assertFalse(task.is_overdue(50.0))
self.assertFalse(task.is_overdue(100.0))
self.assertTrue(task.is_overdue(150.0))
def test_is_overdue_no_deadline(self):
"""Test checking overdue status for task without deadline."""
task = Task("T1", priority=10, arrival_time=0.0)
self.assertFalse(task.is_overdue(1000.0))
def test_time_until_deadline(self):
"""Test calculating time until deadline."""
task = Task("T1", priority=10, arrival_time=0.0, deadline=100.0)
self.assertEqual(task.time_until_deadline(50.0), 50.0)
self.assertEqual(task.time_until_deadline(100.0), 0.0)
self.assertEqual(task.time_until_deadline(150.0), 0.0)
def test_time_until_deadline_no_deadline(self):
"""Test time until deadline for task without deadline."""
task = Task("T1", priority=10, arrival_time=0.0)
self.assertIsNone(task.time_until_deadline(100.0))
if __name__ == '__main__':
unittest.main()