C語言順序棧的基本操作

#include<stdio.h>
#include<stdlib.h>
#define max 1000
typedef struct
{
	int elem[max];
	int top;
}SeqStack;

//置空棧 
SeqStack *InitStack(){
	SeqStack *s;
	s=(SeqStack *)malloc(sizeof(SeqStack));
	s->top=-1;
	return s;
}

//判空棧
int Empty(SeqStack *s){
	if(s->top==-1) return 1;
	return 0;
} 

//入棧
int Push(SeqStack *s,int x){
	if(s->top==max-1) return 0;
	else{
		s->top++;
		s->elem[s->top]=x;
		return 1;
	}
} 

//出棧
int Pop(SeqStack *s,int *x){
	if(Empty(s)) return 0;
	else{
		*x=s->elem[s->top];
		s->top--;
		return 1;
	}
}

//取棧頂元素
int GetTop(SeqStack *s){
	if(Empty(s)) return 0;
	else return (s->elem[s->top]);
}

main(){
	SeqStack *q;
	q=InitStack();;
	int a;
	scanf("%d",&a);
	while(a != -1){
		Push(q,a);
		scanf("%d",&a);
	}
	int b=GetTop(q);
	printf("棧頂元素是:%d\n",b);
	int y;
	Pop(q,&y);
	printf("出棧的數據元素是:%d\n",y);
	int c=GetTop(q);
	printf("此時棧頂元素是:%d\n",c);
}