Merge pull request TheAlgorithms#304 from hytae1993/master

quicksort_3_partition

Author: harshildarji

sorts/quick_sort_3partition.py

@@ -0,0 +1,31 @@
+from __future__ import print_function
+
+def quick_sort_3partition(sorting, left, right):
+    if right <= left:
+        return
+    a = i = left
+    b = right
+    pivot = sorting[left]
+    while i <= b:
+        if sorting[i] < pivot:
+            sorting[a], sorting[i] = sorting[i], sorting[a]
+            a += 1
+            i += 1
+        elif sorting[i] > pivot:
+            sorting[b], sorting[i] = sorting[i], sorting[b]
+            b -= 1
+        else:
+            i += 1
+    quick_sort_3partition(sorting, left, a - 1)
+    quick_sort_3partition(sorting, b + 1, right)
+
+if __name__ == '__main__':
+    try:
+        raw_input          # Python 2
+    except NameError:
+        raw_input = input  # Python 3
+
+    user_input = raw_input('Enter numbers separated by a comma:\n').strip()
+    unsorted = [ int(item) for item in user_input.split(',') ]
+    quick_sort_3partition(unsorted,0,len(unsorted)-1)
+    print(unsorted)