Initial commit: Randomized Quicksort and Hash Table with Chaining implementation

- Implemented Randomized Quicksort algorithm with performance analysis
- Implemented Hash Table with Chaining for collision resolution
- Added comprehensive test suite (30+ test cases)
- Created test runner script with multiple test options
- Added detailed README with architecture diagrams and documentation
- Added MIT License
- Includes examples and comprehensive documentation
This commit is contained in:
Carlos Gutierrez
2025-11-04 21:35:02 -05:00
commit a7fe11fd74
12 changed files with 2024 additions and 0 deletions

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tests/__init__.py Normal file
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"""
Test suite for MSCS532 Assignment 3 implementations.
"""

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tests/test_hash_table.py Normal file
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"""
Unit tests for Hash Table with Chaining implementation.
"""
import unittest
from src.hash_table import HashTable, HashNode
class TestHashTable(unittest.TestCase):
"""Test cases for hash table with chaining."""
def test_initialization(self):
"""Test hash table initialization."""
ht = HashTable(initial_size=16)
self.assertEqual(ht.size, 16)
self.assertEqual(len(ht), 0)
self.assertEqual(ht.get_load_factor(), 0.0)
def test_insert_and_get(self):
"""Test basic insert and get operations."""
ht = HashTable()
ht.insert(1, "apple")
ht.insert(2, "banana")
self.assertEqual(ht.get(1), "apple")
self.assertEqual(ht.get(2), "banana")
self.assertEqual(len(ht), 2)
def test_insert_update(self):
"""Test that inserting same key updates value."""
ht = HashTable()
ht.insert(1, "apple")
ht.insert(1, "banana")
self.assertEqual(ht.get(1), "banana")
self.assertEqual(len(ht), 1)
def test_get_nonexistent_key(self):
"""Test getting a key that doesn't exist."""
ht = HashTable()
ht.insert(1, "apple")
self.assertIsNone(ht.get(2))
def test_delete_existing_key(self):
"""Test deleting an existing key."""
ht = HashTable()
ht.insert(1, "apple")
ht.insert(2, "banana")
deleted = ht.delete(1)
self.assertTrue(deleted)
self.assertIsNone(ht.get(1))
self.assertEqual(ht.get(2), "banana")
self.assertEqual(len(ht), 1)
def test_delete_nonexistent_key(self):
"""Test deleting a key that doesn't exist."""
ht = HashTable()
ht.insert(1, "apple")
deleted = ht.delete(2)
self.assertFalse(deleted)
self.assertEqual(len(ht), 1)
def test_contains(self):
"""Test contains method."""
ht = HashTable()
ht.insert(1, "apple")
self.assertTrue(ht.contains(1))
self.assertFalse(ht.contains(2))
def test_in_operator(self):
"""Test using 'in' operator."""
ht = HashTable()
ht.insert(1, "apple")
self.assertIn(1, ht)
self.assertNotIn(2, ht)
def test_load_factor(self):
"""Test load factor calculation."""
ht = HashTable(initial_size=4)
# Initially empty
self.assertEqual(ht.get_load_factor(), 0.0)
# Add elements
ht.insert(1, "a")
self.assertEqual(ht.get_load_factor(), 0.25)
ht.insert(2, "b")
self.assertEqual(ht.get_load_factor(), 0.5)
ht.insert(3, "c")
self.assertEqual(ht.get_load_factor(), 0.75)
def test_resize(self):
"""Test automatic resizing when load factor threshold is reached."""
ht = HashTable(initial_size=4, load_factor_threshold=0.75)
# Insert elements to trigger resize
ht.insert(1, "a")
ht.insert(2, "b")
ht.insert(3, "c")
# This should trigger resize (3/4 = 0.75)
ht.insert(4, "d")
# Size should have doubled
self.assertEqual(ht.size, 8)
# All elements should still be accessible
self.assertEqual(ht.get(1), "a")
self.assertEqual(ht.get(2), "b")
self.assertEqual(ht.get(3), "c")
self.assertEqual(ht.get(4), "d")
self.assertEqual(len(ht), 4)
def test_get_all_items(self):
"""Test getting all items from hash table."""
ht = HashTable()
ht.insert(1, "apple")
ht.insert(2, "banana")
ht.insert(3, "cherry")
items = ht.get_all_items()
self.assertEqual(len(items), 3)
# Check that all items are present
item_dict = dict(items)
self.assertEqual(item_dict[1], "apple")
self.assertEqual(item_dict[2], "banana")
self.assertEqual(item_dict[3], "cherry")
def test_collision_handling(self):
"""Test that collisions are handled correctly."""
ht = HashTable(initial_size=5)
# Insert keys that might collide
keys = [1, 6, 11, 16, 21]
for key in keys:
ht.insert(key, f"value_{key}")
# All keys should be retrievable
for key in keys:
self.assertEqual(ht.get(key), f"value_{key}")
self.assertEqual(len(ht), len(keys))
def test_delete_from_chain(self):
"""Test deleting an element from the middle of a chain."""
ht = HashTable(initial_size=5)
# Create a chain by inserting colliding keys
keys = [1, 6, 11]
for key in keys:
ht.insert(key, f"value_{key}")
# Delete middle element
deleted = ht.delete(6)
self.assertTrue(deleted)
# Remaining elements should still be accessible
self.assertEqual(ht.get(1), "value_1")
self.assertIsNone(ht.get(6))
self.assertEqual(ht.get(11), "value_11")
self.assertEqual(len(ht), 2)
def test_len(self):
"""Test __len__ method."""
ht = HashTable()
self.assertEqual(len(ht), 0)
ht.insert(1, "a")
self.assertEqual(len(ht), 1)
ht.insert(2, "b")
self.assertEqual(len(ht), 2)
ht.delete(1)
self.assertEqual(len(ht), 1)
def test_multiple_operations(self):
"""Test a sequence of mixed operations."""
ht = HashTable()
# Insert
ht.insert(1, "one")
ht.insert(2, "two")
ht.insert(3, "three")
# Update
ht.insert(2, "TWO")
# Delete
ht.delete(1)
# Verify final state
self.assertIsNone(ht.get(1))
self.assertEqual(ht.get(2), "TWO")
self.assertEqual(ht.get(3), "three")
self.assertEqual(len(ht), 2)
def test_empty_hash_table(self):
"""Test operations on empty hash table."""
ht = HashTable()
self.assertIsNone(ht.get(1))
self.assertFalse(ht.contains(1))
self.assertFalse(ht.delete(1))
self.assertEqual(ht.get_all_items(), [])
self.assertEqual(len(ht), 0)
if __name__ == '__main__':
unittest.main()

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tests/test_quicksort.py Normal file
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"""
Unit tests for Randomized Quicksort implementation.
"""
import unittest
import random
from src.quicksort import (
randomized_quicksort,
partition,
randomized_partition,
compare_with_builtin,
analyze_performance
)
class TestRandomizedQuicksort(unittest.TestCase):
"""Test cases for randomized quicksort algorithm."""
def test_empty_array(self):
"""Test sorting an empty array."""
arr = []
result = randomized_quicksort(arr)
self.assertEqual(result, [])
def test_single_element(self):
"""Test sorting an array with a single element."""
arr = [42]
result = randomized_quicksort(arr)
self.assertEqual(result, [42])
def test_sorted_array(self):
"""Test sorting an already sorted array."""
arr = [1, 2, 3, 4, 5]
result = randomized_quicksort(arr)
self.assertEqual(result, [1, 2, 3, 4, 5])
def test_reverse_sorted_array(self):
"""Test sorting a reverse sorted array."""
arr = [5, 4, 3, 2, 1]
result = randomized_quicksort(arr)
self.assertEqual(result, [1, 2, 3, 4, 5])
def test_random_array(self):
"""Test sorting a random array."""
arr = [64, 34, 25, 12, 22, 11, 90, 5]
result = randomized_quicksort(arr)
expected = sorted(arr)
self.assertEqual(result, expected)
def test_duplicate_elements(self):
"""Test sorting an array with duplicate elements."""
arr = [3, 1, 4, 1, 5, 9, 2, 6, 5, 3]
result = randomized_quicksort(arr)
expected = sorted(arr)
self.assertEqual(result, expected)
def test_negative_numbers(self):
"""Test sorting an array with negative numbers."""
arr = [-5, -2, -8, 1, 3, -1, 0]
result = randomized_quicksort(arr)
expected = sorted(arr)
self.assertEqual(result, expected)
def test_large_array(self):
"""Test sorting a large array."""
arr = [random.randint(1, 10000) for _ in range(1000)]
result = randomized_quicksort(arr)
expected = sorted(arr)
self.assertEqual(result, expected)
def test_original_array_not_modified(self):
"""Test that the original array is not modified."""
arr = [64, 34, 25, 12, 22, 11, 90, 5]
original = arr.copy()
randomized_quicksort(arr)
self.assertEqual(arr, original)
def test_all_same_elements(self):
"""Test sorting an array with all same elements."""
arr = [5, 5, 5, 5, 5]
result = randomized_quicksort(arr)
self.assertEqual(result, [5, 5, 5, 5, 5])
class TestPartition(unittest.TestCase):
"""Test cases for partition function."""
def test_partition(self):
"""Test partition function."""
arr = [64, 34, 25, 12, 22, 11, 90, 5]
pivot_idx = partition(arr, 0, len(arr) - 1)
# Check that pivot is in correct position
pivot_value = arr[pivot_idx]
# All elements before pivot should be <= pivot
for i in range(0, pivot_idx):
self.assertLessEqual(arr[i], pivot_value)
# All elements after pivot should be >= pivot
for i in range(pivot_idx + 1, len(arr)):
self.assertGreaterEqual(arr[i], pivot_value)
def test_randomized_partition(self):
"""Test randomized partition function."""
arr = [64, 34, 25, 12, 22, 11, 90, 5]
pivot_idx = randomized_partition(arr, 0, len(arr) - 1)
# Check that pivot is in correct position
pivot_value = arr[pivot_idx]
# All elements before pivot should be <= pivot
for i in range(0, pivot_idx):
self.assertLessEqual(arr[i], pivot_value)
# All elements after pivot should be >= pivot
for i in range(pivot_idx + 1, len(arr)):
self.assertGreaterEqual(arr[i], pivot_value)
class TestPerformanceComparison(unittest.TestCase):
"""Test cases for performance comparison utilities."""
def test_compare_with_builtin(self):
"""Test comparison with built-in sort."""
arr = [random.randint(1, 1000) for _ in range(100)]
comparison = compare_with_builtin(arr)
self.assertIn('quicksort_time', comparison)
self.assertIn('builtin_time', comparison)
self.assertIn('speedup', comparison)
self.assertIn('is_correct', comparison)
self.assertIn('array_length', comparison)
self.assertTrue(comparison['is_correct'])
self.assertEqual(comparison['array_length'], 100)
self.assertGreater(comparison['quicksort_time'], 0)
self.assertGreater(comparison['builtin_time'], 0)
def test_analyze_performance(self):
"""Test performance analysis."""
results = analyze_performance([100, 1000])
self.assertEqual(len(results), 2)
for result in results:
self.assertIn('quicksort_time', result)
self.assertIn('builtin_time', result)
self.assertIn('is_correct', result)
self.assertTrue(result['is_correct'])
if __name__ == '__main__':
unittest.main()