c语言实现顺序栈

//c++实现顺序栈
#include<iostream>
using namespace std;
#define maxsize 20
typedef struct stack
{
int top;
int a[maxsize];
}stack;
void initstack(stack* s)
{
s->top=-1;
}
bool isempty(stack* s)
{
if(s->top==-1)
return true;
else
return false;
}
bool isfull(stack* s)
{
if(s->top>maxsize-1)
return true;
else
return false;
}
void push(stack* s,int i)
{
if(!isfull(s))
{
s->a[++s->top]=i;
}
}
int pop(stack*s)
{
if(!isempty(s))
{
int re=s->a[s->top];
s->top--;
return re;
}

}
void main()
{
stack s;
initstack(&s);
push(&s,1);
push(&s,2);
push(&s,3);
int re=pop(&s);
cout<<re<<endl;
}