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

#define MAX_SIZE 100

typedef struct Stack Stack;

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

    void (*push)(Stack *s, int value);
    int (*pop)(Stack *s);
    bool (*isEmpty)(Stack *s);
};

void _push(Stack *s, int value){
    if(s->top == MAX_SIZE-1){
        printf("Stack is full!");
        return;
    }
    s->data[++(s->top)] = value;
    printf("stack : ");
    for(int i=0; i<=s->top; i++){
        printf("%d ",s->data[i]);
    }
    printf("\n");
}

int _pop(Stack *s){
    if(s->top == -1){
        printf("Stack is empty ");
        return -1;
    }
    return s->data[(s->top)--];
}

bool _isEmpty(Stack *s){
    return s->top == -1;
}

Stack creatStack(){
    Stack s;
    s.top = -1;
    s.push = _push;
    s.pop = _pop;
    s.isEmpty = _isEmpty;
    return s;
}

int main(){
    Stack stack = creatStack();
    while(true){
        char input[10]; 
        
        printf("\n명령을 입력하세요 (push, pop, isEmpty, exit): ");
        scanf("%s", input);

        if(!strcmp(input, "push")){
            int value;
            printf("스택에 넣을 값을 입력해주세요 : ");
            scanf("%d", &value);
            stack.push(&stack, value);
        }
        else if(!strcmp(input, "pop")){
            int poppedValue = stack.pop(&stack);

            if(poppedValue != -1){
                printf("Pop value : %d\n", poppedValue);
            }
        }
        else if(!strcmp(input, "isEmpty")){
            printf("%s\n", stack.isEmpty(&stack) ? "스택이 비었습니다" : "스택이 비어있지 않습니다.");
        }
        else {
            printf("종료합니다\n");
            break;
        }
    }
    return 0;
}