用类实现贪吃蛇游戏C++

以下一个简单的贪吃蛇游戏的C++代码实现，使用了面向对象编程的思想，利用类来实现游戏的各个功能：

#include <iostream>
#include <cstdlib>
#include <ctime>
#include <conio.h>
#include <windows.h>

using namespace std;

class Snake
{
public:
    Snake(int x = 10, int y = 10) : length(1), direction(0)
    {
        body[0].x = x;
        body[0].y = y;
    }
    void move()
    {
        for (int i = length; i > 0; i--)
        {
            body[i].x = body[i - 1].x;
            body[i].y = body[i - 1].y;
        }
        switch (direction)
        {
        case 0: // up
            body[0].y--;
            break;
        case 1: // down
            body[0].y++;
            break;
        case 2: // left
            body[0].x--;
            break;
        case 3: // right
            body[0].x++;
            break;
        }
    }
    void changeDirection(char key)
    {
        switch (key)
        {
        case 'w':
            if (direction != 1) // can't go down
                direction = 0;
            break;
        case 's':
            if (direction != 0) // can't go up
                direction = 1;
            break;
        case 'a':
            if (direction != 3) // can't go right
                direction = 2;
            break;
        case 'd':
            if (direction != 2) // can't go left
                direction = 3;
            break;
        }
    }
    bool eat(Food &food)
    {
        if (body[0].x == food.x && body[0].y == food.y)
        {
            length++;
            return true;
        }
        return false;
    }
    bool hitWall()
    {
        if (body[0].x < 0 || body[0].x >= WIDTH || body[0].y < 0 || body[0].y >= HEIGHT)
            return true;
        return false;
    }
    bool hitBody()
    {
        for (int i = 1; i < length; i++)
        {
            if (body[0].x == body[i].x && body[0].y == body[i].y)
            {
                return true;
            }
        }
        return false;
    }
public:
    struct Point
    {
        int x;
        int y;
    };
    static const int WIDTH = 20;
    static const int HEIGHT = 20;
    Point body[WIDTH * HEIGHT];
    int length;
    int direction;
};

class Food
{
public:
    Food() : x(0), y(0) {}
    void generate(Snake &snake)
    {
        srand(time(NULL));
        do
        {
            x = rand() % Snake::WIDTH;
            y = rand() % Snake::HEIGHT;
        } while (isOnSnake(snake));
    }
    bool isOnSnake(Snake &snake)
    {
        for (int i = 0; i < snake.length; i++)
        {
            if (snake.body[i].x == x && snake.body[i].y == y)
            {
                return true;
            }
        }
        return false;
    }
public:
    int x;
    int y;
};

class Game
{
public:
    Game() : score(0), isOver(false) {}
    void start()
    {
        snake = Snake(Snake::WIDTH / 2, Snake::HEIGHT / 2);
        food.generate(snake);
        while (!isOver)
        {
            system("cls"); // clear console
            draw();
            processInput();
            update();
            Sleep(100); // wait for 100ms
        }
        cout << "Game over!" << endl;
    }
    void draw()
    {
        for (int i = 0; i <= Snake::HEIGHT; i++)
        {
            for (int j = 0; j <= Snake::WIDTH; j++)
            {
                if (i == 0 || i == Snake::HEIGHT || j == 0 || j == Snake::WIDTH)
                {
                    cout << "#";
                }
                else if (i == food.y && j == food.x)
                {
                    cout << "F";
                }
                else
                {
                    bool isBody = false;
                    for (int k = 0; k < snake.length; k++)
                    {
                        if (snake.body[k].x == j && snake.body[k].y == i)
                        {
                            cout << "O";
                            isBody = true;
                            break;
                        }
                    }
                    if (!isBody)
                    {
                        cout << " ";
                    }
                }
            }
            cout << endl;
        }
        cout << "Score: " << score << endl;
    }
    void processInput()
    {
        if (_kbhit())
        {
            char key = _getch();
            snake.changeDirection(key);
        }
    }
    void update()
    {
        snake.move();
        if (snake.hitWall() || snake.hitBody())
        {
            isOver = true;
            return;
        }
        if (snake.eat(food))
        {
            score += 10;
            food.generate(snake);
        }
    }
public:
    Snake snake;
    Food food;
    int score;
    bool isOver;
};

int main()
{
    Game game;
    game.start();
    return 0;
}

该代码实现了以下功能：

- Snake类：表示游戏中的蛇，包括蛇的身体、长度、方向等信息。实现了蛇的移动、改变方向、吃食物、撞墙、撞身体等功能。
- Food类：表示游戏中的食物，包括食物的坐标信息。实现了随机生成食物、判断食物是否在蛇身上等功能。
- Game类：表示整个游戏，包括蛇、食物、分数、游戏是否结束等信息。实现了游戏的开始、绘制、处理输入、更新等功能。

在main函数中，我们创建一个Game对象并调用其start方法，即可开始游戏。

该代码还有很多可以改进的地方，比如加入音效、增加难度等等，读者可以自行尝试。