class.c

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include"stack.h"

void init_class(stack *S)
{
	(*S).a=(int*)malloc(100*sizeof(int));
	(*S).len=0;
	(*S).top=_top;
	(*S).pop=_pop;
	(*S).push=_push;
	(*S).print=_print;
}

int main()
{
	stack S;
	init_class(&S);

	char command[10];
	while(scanf("%s", command)!=EOF)
	{
		if(strcmp(command, "push")==0)
		{
			int n;
			scanf("%d", &n);
			S.push(&S, n);
		}
		else if(strcmp(command, "pop")==0)
			S.pop(&S);
		else if(strcmp(command, "top")==0)
			printf("%d\n", S.top(&S));
		else if(strcmp(command, "print")==0)
			S.print(&S);
	}
}