Stack.c

/*
    Below we have a simple "C" program implementing 
    stack data structure
*/
#include<stdio.h>
#include<process.h>
#include<stdlib.h>

#define MAX 5	//Maximum number of elements that can be stored

int top=-1,stack[MAX];
void push();
void pop();
void display();

void main()
{
	int ch;

	while(1)	//infinite loop, will end when choice will be 4
	{
		printf("\n*** Stack Menu ***");
		printf("\n\n1.Push\n2.Pop\n3.Display\n4.Exit");
		printf("\n\nEnter your choice(1-4):");
		scanf("%d",&ch);

		switch(ch)
		{
			case 1:
				push();
				break;
			case 2:
				pop();
				break;
			case 3:
				display();
				break;
			case 4:
				exit(0);

			default:
				printf("\nWrong Choice!!");
		}
	}
}
void push()
{
	int val;

	if(top==MAX-1)
	{
		printf("\nStack is full!!");
	}
	else
	{
		printf("\nEnter element to push:");
		scanf("%d",&val);
		top=top+1;
		stack[top]=val;
	}
}
void pop()
{
	if(top==-1)
	{
		printf("\nStack is empty!!");
	}
	else
	{
		printf("\nDeleted element is %d",stack[top]);
		top=top-1;
	}
}
void display()
{
	int i;

	if(top==-1)
	{
		printf("\nStack is empty!!");
	}
	else
	{
		printf("\nStack is...\n");
		for(i=top;i>=0;--i)
			printf("%d\n",stack[i]);
	}
}