Example

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

#define size 5

void pop();
void push();
void display();

 struct stack
  {
   int item;
   int stack[size];
  }s;

  int top=-1;

  void push()
  {
  if(top==size-1)
  {
  printf("\n stack is full");
  }
  else
  {
  top=top+1;
  printf("\n\n Enter element in stack: ");
  scanf("%d",&s.item);
  s.stack[top]=s.item;
  }
  }

  void pop()
  {
  if(top==0)
  {
  printf("\nStack is empty: ");
  }
  else
  {
  s.item=s.stack[top];
  top=top-1;
  printf("deleted data is: %d",s.item);
  }
  }

  void display()
  {
   int i;
   if(top==0)
   {
   printf("\n Stack is empty: ");
   }
   else
   {
    for(i=top;i>0;i--)
    {
    printf("\n%d",s.stack[i]);
    }
   }
  }

  void main()
  {
   char ch,c;

   do
   {
   u:
   clrscr();
   printf("\n\n1: push");
   printf("\n2: pop");
   printf("\n3: display");
   printf("\n4: exit");
   printf("\nenter your choice: ");
   scanf("%d",&ch);
   switch(ch)
   {
    case 1:
  up:
  push();
  break;
    case 2:
  pop();
  break;
    case 3:
  display();
  break;
    case 4:
  exit(0);
  break;
    default:
  printf("\nwrong choice");
   }
   printf("\n\n Pushed an element (Y/N)");
   c=getch();
   if(c=='y'||c=='Y')
   {
   goto up;
   }
   else
   {
   goto u;
   }
   }
   while(ch!=5);
  }