#include <stdio.h>
#include <stdlib.h>
#include "data_structures.h"

struct point *head;

void
push(int x, int y, char c)
{
	struct point *tmp = malloc(sizeof(struct point));
	tmp->c = c;
	tmp->x = x;
	tmp->y = y;
	tmp->next = head;
	head = tmp;
}

char
pop()
{
	if (head == NULL) {
		return -1;
	}
	struct point *tmp = head;
	char c = tmp->c;
	head = head->next;
	free(tmp);
	return c;
}