Quick Sort

#include<stdio.h>

#include<sys/time.h>

#define max 20

void quick(int [],int ,int);

void main()

{

            int a[max],i,n;

            int t1,t2;

            struct timeval tt;

            struct timezone tz;

           

            printf("How many element you want to short: ");

            scanf("%d",&n);

            printf("Enter array: ");

            for(i=0;i<n;i++)

               scanf("%d",&a[i]);

           

            gettimeofday(&tt,&tz);

            t1=tt.tv_usec;

            quick(a,0,n-1);

            gettimeofday(&tt,&tz);

            t2=tt.tv_usec;

           

            printf("\n\nTime required= %d\n",t2-t1);

            for(i=0;i<n;i++)

              printf("%d ",a[i]);

}

void quick(int a[],int low,int high)

{

            int i,j,t,pivot;

            if(low<high)

           {

                        pivot=low;

                        i=low;

                        j=high;            

                        while(i<j)

                         {

                                    while((a[i]<=a[pivot]) && (i<high))

                                                i++;

                                    while(a[j]>a[pivot])

                                                j--;

                                    if(i<j)

                                   {

                                                t=a[i];

                                                a[i]=a[j];

                                                a[j]=t;

                                    }

                        }

                        t=a[pivot];

                        a[pivot]=a[j];

                        a[j]=t; 

                        quick(a,low,j-1);

                        quick(a,j+1,high);

    }

Output :-