/* 

StackAsArray.c 
Author: W. M. Farmer
Revised: January 27, 2007

Description: A stack module implemented as an array.

*/

#include <stdio.h>
#define MAX 1000


/* Module variables */

static int stack[MAX];                                  /* Stack as array. */
static int height = 0;                                 /* Height of stack. */

/* Selectors */

int stack_top() {
  if (height != 0)
    return stack[height - 1];
  else {
    printf("Error in stack_top(): Stack is empty.\n");
    return 0;
  }
}

int stack_height() {
  return height;
}

/* Mutators */

void stack_push(int element) {
  if (height != MAX) {
    stack[height] = element;
    height = height + 1;
  }
  else
    printf("Error in stack_push(%d): Stack is full.\n", element);
}

void stack_pop() {
  if (height != 0)
    height = height - 1;
  else
    printf("Error in stack_pop(): Stack is empty.\n");
}

/* Print procedure */

void stack_print() {
  int i;
  printf("Stack contents: [");
  for (i = 0; i < height; i++) {
    if (i + 1 == height)
      printf("%d", stack[i]);
    else
      printf("%d,", stack[i]);
  }
  printf("].\n");
}