Answers for "quicksort algorithm in python"

Quick Sort python

def partition(array, begin, end):
    pivot_idx = begin
    for i in xrange(begin+1, end+1):
        if array[i] <= array[begin]:
            pivot_idx += 1
            array[i], array[pivot_idx] = array[pivot_idx], array[i]
    array[pivot_idx], array[begin] = array[begin], array[pivot_idx]
    return pivot_idx

def quick_sort_recursion(array, begin, end):
    if begin >= end:
        return
    pivot_idx = partition(array, begin, end)
    quick_sort_recursion(array, begin, pivot_idx-1)
    quick_sort_recursion(array, pivot_idx+1, end)

def quick_sort(array, begin=0, end=None):
    if end is None:
        end = len(array) - 1
    
    return quick_sort_recursion(array, begin, end)

quicksort code in python

#this function is for getting correct position of pivot
def pivot_place(list1,first,last):
    pivot = list1[first]
    left = first + 1
    right = last

    while True :

        while left <= right and  list1[left] <= pivot :
            left += 1
        while left<=right and list1[right] >= pivot:
            right -= 1

        if right < left :
            break
        else:
            list1[left],list1[right] = list1[right],list1[left]
    list1[first],list1[right] = list1[right],list1[first]

    return right
def quicksort(list1,first,last):
    if first < last :
        p = pivot_place(list1,first,last)
        quicksort(list1,first,p-1)
        quicksort(list1,p+1,last)
n = int(input("How many elements you want : "))
list1 = [int(input("Enter elements : ")) for x in range(n)]
quicksort(list1,0,n - 1)
print(list1)

Quick Sort Algorithm in Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

def quickSort(alist):
   quickSortHelper(alist,0,len(alist)-1)

def quickSortHelper(alist,first,last):
   if first<last:

       splitpoint = partition(alist,first,last)

       quickSortHelper(alist,first,splitpoint-1)
       quickSortHelper(alist,splitpoint+1,last)


def partition(alist,first,last):
   pivotvalue = alist[first]

   leftmark = first+1
   rightmark = last

   done = False
   while not done:

       while leftmark <= rightmark and alist[leftmark] <= pivotvalue:
           leftmark = leftmark + 1

       while alist[rightmark] >= pivotvalue and rightmark >= leftmark:
           rightmark = rightmark -1

       if rightmark < leftmark:
           done = True
       else:
           temp = alist[leftmark]
           alist[leftmark] = alist[rightmark]
           alist[rightmark] = temp

   temp = alist[first]
   alist[first] = alist[rightmark]
   alist[rightmark] = temp


   return rightmark