Create quick_sort_with_testing.py

Implemented the quick sort and also included the test cases to check for the edge case where it satisfies the algorithm.

divide_and_conquer/quick_sort_with_testing.py

@@ -0,0 +1,55 @@
+def partition(arr, low, high):
+    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 quick_sort(arr, low, high):
+    if low < high:
+        pi = partition(arr, low, high)
+        quick_sort(arr, low, pi - 1)
+        quick_sort(arr, pi + 1, high)
+
+# Function to handle edge cases and testing
+def test_quick_sort():
+    test_cases = [
+        # Regular case with positive integers
+        ([10, 7, 8, 9, 1, 5], [1, 5, 7, 8, 9, 10]),
+
+        # Already sorted array
+        ([1, 2, 3, 4, 5], [1, 2, 3, 4, 5]),
+
+        # Reverse sorted array
+        ([5, 4, 3, 2, 1], [1, 2, 3, 4, 5]),
+
+        # Array with duplicates
+        ([4, 2, 4, 1, 2, 1], [1, 1, 2, 2, 4, 4]),
+
+        # Array with negative and positive numbers
+        ([-3, 5, -1, 7, 0, -2], [-3, -2, -1, 0, 5, 7]),
+
+        # Single element array
+        ([42], [42]),
+
+        # Empty array
+        ([], []),
+
+        # Array with all same elements
+        ([1, 1, 1, 1], [1, 1, 1, 1])
+    ]
+    
+    for i, (arr, expected) in enumerate(test_cases):
+        print(f"Test case {i+1}: Original array = {arr}")
+        quick_sort(arr, 0, len(arr) - 1)
+        assert arr == expected, f"Test case {i+1} failed: Expected {expected}, but got {arr}"
+        print(f"Test case {i+1} passed: Sorted array = {arr}")
+    
+    print("All test cases passed!")
+
+test_quick_sort()