stack

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#include <string.h>

#define MAX 100

int t, i, j = 0, k, l, a, b, c, d, n, x, y, z;
int ar[MAX];
int top = 0;

void stack()
{
	puts("Press Any key to continue");
	puts("1 --> push");
	puts("2 --> pop");
	puts("3 --> exit");
}

void push()
{
	if (j >= MAX) printf("Stack full\n");
	else
	{
		printf("Item to push:");
		scanf("%d", &ar[j]);
		j++;
		top = j;
		printf("Item %d has been pushed\n", ar[j - 1]);
	}
}

int pop()
{
	if (top == 0) {puts("Stack empty, invalid operation"); return 0;}
	else
	{
		x = ar[j - 1];
		ar[j - 1] = 0;
		j--;
		return x;
	}
}

int main()
{
	for (; ;)
	{
		void stack();
		scanf("%d", &n);
		if (n == 3) break;
		if (n == 1)
		{
			push();
		}
		else if (n == 2)
		{
			z = pop();
			if (z)printf("Item %d has been popped\n", z);

		}
		else puts("Ooops...try again");
	}
	for (i = 0; i < j; i++)
		printf("%d ", ar[j]);
	puts("");
	return 0;
}