QuickSort.py finally approved

Author: armanjscript

DataStructures/Section10/QuickSort.py

@@ -0,0 +1,36 @@
+def partition(unsorted_array, first_index, last_index):
+    pivot = unsorted_array[first_index]
+    pivot_index = first_index
+    index_of_last_element = last_index
+    less_than_pivot_index = index_of_last_element
+    greater_than_pivot_index = first_index + 1
+
+    while True:
+        while unsorted_array[greater_than_pivot_index] < pivot and greater_than_pivot_index < last_index:
+            greater_than_pivot_index += 1
+        while unsorted_array[less_than_pivot_index] > pivot and less_than_pivot_index >= first_index:
+            less_than_pivot_index -=1
+        if greater_than_pivot_index < less_than_pivot_index:
+            temp = unsorted_array[greater_than_pivot_index]
+            unsorted_array[greater_than_pivot_index] = unsorted_array[less_than_pivot_index]
+            unsorted_array[less_than_pivot_index] = temp
+        else:
+            break
+    unsorted_array[pivot_index] = unsorted_array[less_than_pivot_index]
+    unsorted_array[less_than_pivot_index] = pivot
+    return less_than_pivot_index
+
+
+def quicksort(unsorted_array, first, last):
+    if last - first <= 0:
+        return
+    else:
+        partition_point = partition(unsorted_array, first, last)
+        quicksort(unsorted_array, first, partition_point - 1)
+        quicksort(unsorted_array, partition_point + 1, last)
+
+
+my_array = [43, 3, 77, 89, 4, 20]
+print(my_array)
+quicksort(my_array, 0, 5)
+print(my_array)