QUICK SORT PROGRAM

QUICK SORT

#include<stdio.h>

#include<conio.h>

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

void main()

{

int a[10], n, i, lb, ub;

clrscr();

printf("\n Enter the n value: ");

scanf("%d",&n);

printf("\n Enter the %d array elements: ",n);

for(i=1; i<=n ;i++)

scanf("%d",&a[i]);

lb=1;

ub=n+1;

printf("\n Before sorting the given array is:" );

for(i=1; i<=n; i++)

printf("%4d",a[i]);

qsort(a, lb, ub);

printf("\n\n\n After sorting the given array is: ");

for(i=1; i<=n; i++)

printf("%4d",a[i]);

getch();

}

void qsort(int a[ ], int lb, int ub)

{

int flag=1,i,j,temp,pivot;

if(lb<ub)

{

                                   i=lb;

                                   j=ub+1;

                                   pivot=a[lb];

                                   while(flag)

                                   {

                                               i=i+1;

                                               while(a[i]<pivot)

                                               {

                                                           i++;

                                               }

                                                j=j-1;

                                               while(a[j]>pivot)

                                               {

                                                           j--;

                                               }

                                               if(i<j)

                                               {

                                               temp=a[i];

                                               a[i]=a[j];

                                               a[j]=temp;

                                               }

                                               else

                                               {

                                               flag=0;

                                               }

                                   }

                                   temp=a[lb];

                                   a[lb]= a[j];

                                   a[j]=temp;

                                   qsort(a, lb, j-1);

                                   qsort(a, j+1, ub);

}

}

Share on Google Plus