program for Quick sorting in Data structure With Example

Program

#include <stdio.h>
#define MAX 10
void swap(int *x,int *y)
{
   int temp;
   temp = *x;
   *x = *y;
   *y = temp;
}
int getkeyposition(int i,int j )
{
   return((i+j) /2);
}
void qsort(int list[],int m,int n)
{
   int key,i,j,k;
   if( m < n)
   {
      k = getkeyposition(m,n);
      swap(&list[m],&list[k]);
      key = list[m];
      i = m+1;
      j = n;
      while(i <= j)
      {
         while((i <= n) && (list[i] <= key))
                i++;
         while((j >= m) && (list[j] > key))
                j-;
         if( i < j)
                swap(&list[i],&list[j]);
      }
      swap(&list[m],&list[j]);
      qsort(list[],m,j-l);
      qsort(list[],j+1,n);
   }
}
void readlist(int list[],int n)
{
   int i;
   printf("Enter the elements\n");
   for(i=0;i<n;i++)
       scanf("%d",&list[i]);
}
void printlist(int list[],int n)
{
   int i;
   printf("The elements of the list are: \n");
   for(i=0;i<n;i++)
       printf("%d\t",list[i]);
}

void main()
{
   int list[MAX], n;
   printf("Enter the number of elements in the list max = 10\n");
   scanf("%d",&n);
   readlist(list,n);
   printf("The list before sorting is:\n");
   printlist(list,n);
   qsort(list,0,n-1);
   printf("\nThe list after sorting is:\n");
   printlist(list,n);
}

Example

Input

Enter the number of elements in the list, max = 10

10

Enter the elements

7
99
23
11
65
43
23
21
21
77

Output

The list before sorting is:

The elements of the list are:

7 99 23 11 65 43 23 21 21 77

The list after sorting is:

The elements of the list are:

7 11 21 21 23 23 43 65 77 99