飞机大战c语言easyx

以下是一个简单的飞机大战C语言EasyX的例子：

#include <graphics.h>
#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define WIDTH 480
#define HEIGHT 700
#define ENEMY_NUM 5
#define BULLET_NUM 10

IMAGE bg, plane, enemy, bullet;
int score = 0;
int plane_x = WIDTH / 2, plane_y = HEIGHT - 100;
int enemy_x[ENEMY_NUM], enemy_y[ENEMY_NUM];
int bullet_x[BULLET_NUM], bullet_y[BULLET_NUM];
bool bullet_state[BULLET_NUM] = { false };

void init() {
    initgraph(WIDTH, HEIGHT);
    loadimage(&bg, _T("bg.jpg"));
    loadimage(&plane, _T("plane.png"));
    loadimage(&enemy, _T("enemy.png"));
    loadimage(&bullet, _T("bullet.png"));
    srand((unsigned)time(NULL));
    for (int i = 0; i < ENEMY_NUM; i++) {
        enemy_x[i] = rand() % (WIDTH - 50);
        enemy_y[i] = rand() % 200 - 200;
    }
}

void draw() {
    putimage(0, 0, &bg);
    putimage(plane_x, plane_y, &plane);
    for (int i = 0; i < ENEMY_NUM; i++) {
        putimage(enemy_x[i], enemy_y[i], &enemy);
    }
    for (int i = 0; i < BULLET_NUM; i++) {
        if (bullet_state[i]) {
            putimage(bullet_x[i], bullet_y[i], &bullet);
        }
    }
    settextcolor(WHITE);
    settextstyle(20, 0, _T("Consolas"));
    TCHAR str[50];
    _stprintf_s(str, _T("Score: %d"), score);
    outtextxy(10, 10, str);
}

void updateWithoutInput() {
    for (int i = 0; i < ENEMY_NUM; i++) {
        enemy_y[i] += 2;
        if (enemy_y[i] > HEIGHT) {
            enemy_x[i] = rand() % (WIDTH - 50);
            enemy_y[i] = rand() % 200 - 200;
        }
    }
    for (int i = 0; i < BULLET_NUM; i++) {
        if