pra5.c

Quick sort program , It is program for Quick sort algorithm implelementation in C

#include<stdio.h>
#include<conio.h>

void qsort(int[],int,int);
int stackempty();
int pop();
void push();

int s[20],top=-1;

void main()
{
	int a[10],n,i;
	clrscr();
	printf("\n ENTER THE NO OF ELEMENT TO BE SORT: ");
	scanf(" %d",&n);
	for(i=0;i<n;i++)
	{
	  printf("\n ENTER THE ELEMENT: ");
	  scanf("%d",&a[i]);
	}
	qsort(a,0,n-1);
	printf("\n ELEMENT AFTER SORTING: ");
	for(i=0;i<n;i++)
	printf(" %d",a[i]);
	getch();
}

void qsort(int k[10],int lb,int ub)
{
	int flag=1,i,j,temp,key;
	int m=0,pass=0,n=ub;

	push(lb);
	push(ub);
	do
	{
	  ub=pop();
	  lb=pop();
	  if(lb<ub)
	  {
		 i=lb+1;
		 j=ub;
		 key=k[lb];
		 flag=1;
		 while(flag)
		 {
		   while(k[i]<key)
			  i++;
		   while(k[j]>key)
			   j--;
		   if(i<j)
		   {
			 temp=k[i];
			 k[i]=k[j];
			 k[j]=temp;
		   }
		  else
		  flag=0;
	        }

	 temp=k[lb];
	 k[lb]=k[j];
	 k[j]=temp;

	 push(j+1);
	 push(ub);
	 push(lb);
	 push(j-1);

	 pass++;
	 printf("\n\n\n ELEMENT AFTER PASS %d ARE: ",pass);

	 for(m=0;m<=n;m++)
	 printf(" %d",k[m]);

	}

  }while(!stackempty());
}

void push(int data)
{
  top++;
  s[top]=data;

}

int pop()
{
 top--;
 return(s[top+1]);
}

int stackempty()
{
 if(top==-1)
 return(1);
 return(0);
}