Quicksort

Author: ivanmmarkovic

sorting/merge-sort.py

@@ -28,7 +28,7 @@ def merge_sort(nums: list):
         j += 1
         k += 1
 
-    
+
 print(array)
 merge_sort(array)
 print(array)

sorting/quicksort-modify-array.py

@@ -0,0 +1,23 @@
+array = [54, 26, 93, 17, 77, 31, 44, 55, 20]
+
+
+def quick_sort(nums: list) -> list:
+    if len(nums) < 2:
+        return nums
+    pivot_index: int = len(nums) // 2
+    pivot_value: int = nums[pivot_index]
+
+    left: list = []
+    right: list = []
+    for i in range(len(nums)):
+        if i != pivot_index:
+            if nums[i] < pivot_value:
+                left.append(nums[i])
+            else:
+                right.append(nums[i])
+    return quick_sort(left) + [pivot_value] + quick_sort(right)
+
+
+print(array)
+array_sorted: list = quick_sort(array)
+print(array_sorted)

sorting/quicksort.py

@@ -0,0 +1,32 @@
+array = [54, 26, 93, 17, 77, 31, 44, 55, 20]
+
+
+def quick_sort(nums: list, i: int, j: int):
+    if i < j:
+        left: int = i
+        right: int = j
+        pointer: int = left
+        pivot_index: int = left + (right - left) // 2
+        pivot_value: int = nums[pivot_index]
+
+        while pointer <= right:
+            if nums[pointer] < pivot_value:
+                nums[left], nums[pointer] = nums[pointer], nums[left]
+                left += 1
+                pointer += 1
+            elif nums[pointer] > pivot_value:
+                nums[pointer], nums[right] = nums[right], nums[pointer]
+                right -= 1
+            else:
+                pointer += 1
+
+        quick_sort(nums, i, left)
+        if pointer > left:
+            quick_sort(nums, pointer, j)
+        else:
+            quick_sort(nums, pointer + 1, j)
+
+
+print(array)
+quick_sort(array, 0, len(array) - 1)
+print(array)