/*
 * ISA 563, Spring 2011
 * Copyleft by Muhammad Abdulla
 */

#include <stdio.h>

#include "stack2.h"

typedef enum {false, true} bool;

#define MAX 100

int stack_idx = 0;

int stack[MAX];

void stack_push(int item)
{
   if ( stack_idx < MAX ) {
      stack[stack_idx++] = item;
   } else {
      fprintf(stderr, "stack is full, returning.\n");
   }
}

int  stack_pop()
{
   if ( stack_idx > 0 ) {
      return stack[--stack_idx]; 
   } else {
      fprintf(stderr, "stack is empty, returning -1.\n");
      return -1;
   }
}

int stack_empty()
{
   return stack_idx > 0 ? 0 : 1;
}

int stack_full()
{
   return stack_idx < MAX ? 0 : 1;
}