Add comprehensive LeetCode solutions index documentation

src/exercises/22.generate-parentheses.py

@@ -0,0 +1,66 @@
+from string import *
+from re import *
+from datetime import *
+from collections import *
+from heapq import *
+from bisect import *
+from copy import *
+from math import *
+from random import *
+from statistics import *
+from itertools import *
+from functools import *
+from operator import *
+from io import *
+from sys import *
+from json import *
+from builtins import *
+import string
+import re
+import datetime
+import collections
+import heapq
+import bisect
+import copy
+import math
+import random
+import statistics
+import itertools
+import functools
+import operator
+import io
+import sys
+import json
+from typing import *
+
+
+# @leet start
+class Solution:
+    def generateParenthesis(self, n: int) -> List[str]:
+        if n < 1:
+            return []
+        if n == 1:
+            return ["()"]
+
+        stack = []
+        res = []
+        def retrieveParenthesis(open, close):
+            if open == close == n:
+                res.append("".join(stack))
+                return
+            if open < n:
+                stack.append('(')
+                retrieveParenthesis(open + 1, close)
+                stack.pop()
+            if close < open:
+                stack.append(')')
+                retrieveParenthesis(open, close + 1)
+                stack.pop()
+
+        retrieveParenthesis(0, 0)
+
+        return res
+
+
+# @leet end
+