Quick sort using Recursive Function

Write a program to implement Quick sort using recursive approaches. Use randomized element as partitioning element.

/* C implementation Quick Sort using recursive function*/

#include<stdio.h>

void swap(int* a, int* b)

{

    int t = *a;

    *a = *b;

    *b = t;

}

int partition (int arr[], int low, int high)

{

    int pivot = arr[high];    // pivot

    int i = (low - 1),j;  // Index of smaller element

    for (j = low; j <= high- 1; j++)

    {

                if (arr[j] <= pivot)

                {

                    i++;    // increment index of smaller element

                    swap(&arr[i], &arr[j]);

                }

    }

    swap(&arr[i + 1], &arr[high]);

    return (i + 1);

}

void quickSort(int arr[], int low, int high)

{

    if (low < high)

    {

                int pi = partition(arr, low, high);

                quickSort(arr, low, pi - 1);

                quickSort(arr, pi + 1, high);

    }

}

void printArray(int arr[], int size)

{

    int i;

    for (i=0; i < size; i++)

                printf("%d ", arr[i]);

    printf("\n");

}

void main()

{

    int i,arr[20],n;

    clrscr();

    printf("Enter the size of array");

    scanf("%d",&n);

    printf("Enter the array elements ");

    for (i=0;i<n;i++)

    scanf("%d",&arr[i]);

    quickSort(arr, 0, n-1);

    printf("Sorted array: \n");

    printArray(arr, n);

    getch(); 

}

Input & Output 

C implementation QuickSort using recursive function

Enter the size of array

6

Enter the array elements 54 34 32 21 11 8

Sorted array:

8 11 21 32 34 54