c program for quick sorting

#include<stdio.h>

#include<conio.h>

void qsort(int arr[20], int fst, int last);

int main()

{

 int arr[30];

 int i,size;

 printf(“Enter total no. of the elements : “);

 scanf(“%d”,&size);

 printf(“Enter total %d elements : \n”,size);

 for(i=0; i<size; i++)

    scanf(“%d”,&arr[i]);

 qsort(arr,0,size-1);

 printf(“Quick sorted elements are as  : \n”);

 for(i=0; i<size; i++)

    printf(“%d\t”,arr[i]);
getch();

 return 0;

}

void qsort(int arr[20], int fst, int last)

{

 int i,j,pivot,tmp;

 if(fst<last)

 {

   pivot=fst;

   i=fst;

   j=last;

   while(i<j)

   {

     while(arr[i]<=arr[pivot] && i<last)

        i++;

     while(arr[j]>arr[pivot])

        j–;

     if(i<j)

     {

        tmp=arr[i];

        arr[i]=arr[j];

        arr[j]=tmp;

     }

   }

   tmp=arr[pivot];

   arr[pivot]=arr[j];

   arr[j]=tmp;

   qsort(arr,fst,j-1);

   qsort(arr,j+1,last);

 }

}

a program for stack sort (push and pop)

#include <stdio.h>
#define MAX 5
int top, status;
void push (int stack[], int item)
{ if (top == (MAX-1))
status = 0;
else
{ status = 1;
++top;
stack [top] = item;
}
}
int pop (int stack[])
{
int ret;
if (top == -1)
{
status = 0;
}
else
{
status = 1;
ret = stack [top];
–top;
}
return ret;
}
void display (int stack[])
{ int i;
printf (“\nThe Stack is: \n”);
if (top == -1)
printf (“empty”);
else
{
for (i=top; i>=0; –i)
printf (” \n%d “,stack[i]);
}
printf (“\n”);
}
int main()
{
int stack [MAX], item;
int ch;
top = -1;
do
{ do
{
printf (“\nNMAIN MENU:\n”);
printf (“\n 1.PUSH :”);
printf (“\n 2.POP :”);
printf (“\n 3.Exit :”);
printf (“\nEnter Your Choice:\n “);
scanf (“%d”, &ch);
if (ch<1 || ch>3)
printf (“\nInvalid Choice, Please try again:\n”);
} while (ch<1 || ch>3);
switch (ch)
{
case 1:
printf (“\nEnter the Element to be pushed : \n”);
scanf (“%d”, &item);
push (stack, item);
if (status)
{ printf (“\nAfter Pushing :\n”);
display (stack);
if (top == (MAX-1))
printf (“\nThe Stack is Full:\n”);
}
else
printf (“\nStack overflow on Push:\n”);
break;
case 2:
item = pop (stack);
if (status)
{ printf (“\nThe Popped item is %d \n After Popping: “,item);
display (stack);
}
else
printf (“\nStack underflow on Pop:\n”);
break;

}
}while (ch != 3);
}