7.5/stk.c


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#include <stdio.h>
#include <stdlib.h>
#include <error.h>
#include <errno.h>
#include "stk.h"

static unsigned top;
double stk[MAXBUFF];

void push(double n)
{
	if (top < MAXBUFF)
		stk[top++] = n;
	else
		error(EXIT_FAILURE, ENOBUFS, "push");
}

double pop(void)
{
	if (top <= 0)
		error(EXIT_FAILURE, ENOBUFS, "pop");

	return stk[--top];
}

void clear(void)
{
	top = 0;
}