quicksort python code example

Example 1: 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)

Example 2: 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)

Example 3: quicksort in python

def partition(arr, low, high):
    i = (low-1)         
    pivot = arr[high]   
 
	for j in range(low, high):
        if arr[j] <= pivot:
 
            i = i+1
            arr[i], arr[j] = arr[j], arr[i]
 
    arr[i+1], arr[high] = arr[high], arr[i+1]
    return (i+1)
 
def quickSort(arr, low, high):
    if len(arr) == 1:
        return arr
    if low < high:
        pi = partition(arr, low, high)
 
		quickSort(arr, low, pi-1)
        quickSort(arr, pi+1, high)
 
arr = [10, 7, 8, 9, 1, 5]
n = len(arr)
quickSort(arr, 0, n-1)
print("Sorted array is:")
for i in range(n):
    print("%d" % arr[i]),

Example 4: quick sort program in c

#include<stdio.h>
void quicksort(int number[25],int first,int last){
   int i, j, pivot, temp;

   if(first<last){
      pivot=first;
      i=first;
      j=last;

      while(i<j){
         while(number[i]<=number[pivot]&&i<last)
            i++;
         while(number[j]>number[pivot])
            j--;
         if(i<j){
            temp=number[i];
            number[i]=number[j];
            number[j]=temp;
         }
      }

      temp=number[pivot];
      number[pivot]=number[j];
      number[j]=temp;
      quicksort(number,first,j-1);
      quicksort(number,j+1,last);

   }
}

int main(){
   int i, count, number[25];

   printf("How many elements are u going to enter?: ");
   scanf("%d",&count);

   printf("Enter %d elements: ", count);
   for(i=0;i<count;i++)
      scanf("%d",&number[i]);

   quicksort(number,0,count-1);

   printf("Order of Sorted elements: ");
   for(i=0;i<count;i++)
      printf(" %d",number[i]);

   return 0;
}

Example 5: python with quick sort

def quick_sort(array, start, end):
    if start >= end:
        return

    p = partition(array, start, end)
    quick_sort(array, start, p-1)
    quick_sort(array, p+1, end)

Example 6: python with quick sort

array = [29,99,27,41,66,28,44,78,87,19,31,76,58,88,83,97,12,21,44]

quick_sort(array, 0, len(array) - 1)
print(array)