用C++写一个贪吃蛇程序

以下是一个简单的贪吃蛇程序示例，使用C++和SFML库编写：

#include <SFML/Graphics.hpp>
#include <iostream>
#include <vector>

using namespace std;
using namespace sf;

const int WINDOW_WIDTH = 800;
const int WINDOW_HEIGHT = 600;
const int GRID_SIZE = 10;

struct SnakeSegment {
    int x;
    int y;
};

enum class Direction { None, Up, Down, Left, Right };

int main() {
    // Initialize the window
    RenderWindow window(VideoMode(WINDOW_WIDTH, WINDOW_HEIGHT), "Snake Game");
    window.setFramerateLimit(10);

    // Initialize the snake
    vector<SnakeSegment> snake(1, {WINDOW_WIDTH / 2, WINDOW_HEIGHT / 2});
    Direction direction = Direction::None;

    // Initialize the food
    Vector2i food;
    food.x = rand() % (WINDOW_WIDTH / GRID_SIZE) * GRID_SIZE;
    food.y = rand() % (WINDOW_HEIGHT / GRID_SIZE) * GRID_SIZE;
    RectangleShape foodShape({GRID_SIZE, GRID_SIZE});
    foodShape.setFillColor(Color::Red);
    foodShape.setPosition(food.x, food.y);

    while (window.isOpen()) {
        // Handle events
        Event event;
        while (window.pollEvent(event)) {
            if (event.type == Event::Closed) {
                window.close();
            } else if (event.type == Event::KeyPressed) {
                switch (event.key.code) {
                    case Keyboard::Up:
                        direction = Direction::Up;
                        break;
                    case Keyboard::Down:
                        direction = Direction::Down;
                        break;
                    case Keyboard::Left:
                        direction = Direction::Left;
                        break;
                    case Keyboard::Right:
                        direction = Direction::Right;
                        break;
                    default:
                        break;
                }
            }
        }

        // Move the snake
        if (direction != Direction::None) {
            for (int i = snake.size() - 1; i > 0; i--) {
                snake[i].x = snake[i - 1].x;
                snake[i].y = snake[i - 1].y;
            }
            switch (direction) {
                case Direction::Up:
                    snake[0].y -= GRID_SIZE;
                    break;
                case Direction::Down:
                    snake[0].y += GRID_SIZE;
                    break;
                case Direction::Left:
                    snake[0].x -= GRID_SIZE;
                    break;
                case Direction::Right:
                    snake[0].x += GRID_SIZE;
                    break;
                default:
                    break;
            }
        }

        // Check for collision with food
        if (snake[0].x == food.x && snake[0].y == food.y) {
            snake.push_back(snake[snake.size() - 1]);
            food.x = rand() % (WINDOW_WIDTH / GRID_SIZE) * GRID_SIZE;
            food.y = rand() % (WINDOW_HEIGHT / GRID_SIZE) * GRID_SIZE;
            foodShape.setPosition(food.x, food.y);
        }

        // Check for collision with walls and body
        if (snake[0].x < 0 || snake[0].x >= WINDOW_WIDTH || snake[0].y < 0 || snake[0].y >= WINDOW_HEIGHT) {
            window.close();
        }
        for (int i = 1; i < snake.size(); i++) {
            if (snake[0].x == snake[i].x && snake[0].y == snake[i].y) {
                window.close();
            }
        }

        // Clear the window
        window.clear(Color::Black);

        // Draw the food
        window.draw(foodShape);

        // Draw the snake
        RectangleShape segmentShape({GRID_SIZE, GRID_SIZE});
        segmentShape.setFillColor(Color::Green);
        for (int i = 0; i < snake.size(); i++) {
            segmentShape.setPosition(snake[i].x, snake[i].y);
            window.draw(segmentShape);
        }

        // Display the window
        window.display();
    }

    return 0;
}

这个程序使用了SFML图形库来创建窗口并绘制图形。它定义了一个`SnakeSegment`结构体来表示贪吃蛇的每个段落，以及一个`Direction`枚举类型来表示贪吃蛇的方向。在`main()`函数中，它使用`vector`类型来表示整条贪吃蛇，并初始化了窗口、贪吃蛇和食物。

在主循环中，程序首先处理事件，包括关闭窗口和按键事件。如果用户按下方向键，则程序将方向设置为相应的方向。然后，程序根据设置的方向移动贪吃蛇。如果贪吃蛇头部与食物重合，则程序将在贪吃蛇的末尾添加一个节，重新生成食物。

最后，程序绘制食物和贪吃蛇，并检查贪吃蛇是否与窗口边界或自身相撞。如果是，程序将关闭窗口，游戏结束。