用c++，建立一个栈，实现压栈、取栈顶元素、出栈操作

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

#define MAX_SIZE 100

typedef struct {
    int data[MAX_SIZE];
    int top;
} Stack;

void initStack(Stack *s) {
    s->top = -1;
}

int isFull(Stack *s) {
    return s->top == MAX_SIZE - 1;
}

int isEmpty(Stack *s) {
    return s->top == -1;
}

void push(Stack *s, int value) {
    if (isFull(s)) {
        printf("Stack is full.\n");
        return;
    }
    s->top++;
    s->data[s->top] = value;
}

int top(Stack *s) {
    if (isEmpty(s)) {
        printf("Stack is empty.\n");
        return -1;
    }
    return s->data[s->top];
}

int pop(Stack *s) {
    if (isEmpty(s)) {
        printf("Stack is empty.\n");
        return -1;
    }
    int value = s->data[s->top];
    s->top--;
    return value;
}

int main() {
    Stack s;
    initStack(&s);

    push(&s, 1);
    push(&s, 2);
    push(&s, 3);

    printf("Top element: %d\n", top(&s));

    printf("Pop element: %d\n", pop(&s));
    printf("Pop element: %d\n", pop(&s));
    printf("Pop element: %d\n", pop(&s));
    printf("Pop element: %d\n", pop(&s));

    return 0;
}