给我写一个贪吃蛇，用c++

好的，以下是一个简单的贪吃蛇游戏的C++实现：

#include<iostream>
#include<conio.h>
#include<windows.h>
using namespace std;

//定义游戏区域大小
const int width = 20;
const int height = 20;

//定义蛇和食物的坐标
int snakeX[100], snakeY[100], foodX, foodY;

//定义蛇的长度和分数
int snakeLength = 1;
int score = 0;

//定义方向
enum eDirection{STOP = 0, LEFT, RIGHT, UP, DOWN};
eDirection dir;

//初始化游戏
void init()
{
    //初始化蛇的位置在游戏区域中央
    snakeX[0] = width / 2;
    snakeY[0] = height / 2;

    //初始化食物位置
    foodX = rand() % width;
    foodY = rand() % height;

    //初始化方向
    dir = STOP;
}

//绘制游戏区域
void draw()
{
    system("cls");  //清屏

    //绘制上边界
    for (int i = 0; i < width + 2; i++)
        cout << "#";
    cout << endl;

    //绘制游戏区域
    for (int i = 0; i < height; i++)
    {
        for (int j = 0; j < width; j++)
        {
            if (j == 0)
                cout << "#";
            if (i == snakeY[0] && j == snakeX[0])
                cout << "O";  //蛇头
            else if (i == foodY && j == foodX)
                cout << "F";  //食物
            else
            {
                bool print = false;
                for (int k = 1; k < snakeLength; k++)
                {
                    if (snakeX[k] == j && snakeY[k] == i)
                    {
                        cout << "o";  //蛇身
                        print = true;
                    }
                }
                if (!print)
                    cout << " ";
            }
            if (j == width - 1)
                cout << "#";
        }
        cout << endl;
    }

    //绘制下边界
    for (int i = 0; i < width + 2; i++)
        cout << "#";
    cout << endl;

    //显示分数
    cout << "Score:" << score << endl;
}

//获取键盘输入
void input()
{
    if (_kbhit())
    {
        switch (_getch())
        {
        case 'a':
            dir = LEFT;
            break;
        case 'd':
            dir = RIGHT;
            break;
        case 'w':
            dir = UP;
            break;
        case 's':
            dir = DOWN;
            break;
        case 'x':
            dir = STOP;
            break;
        }
    }
}

//游戏逻辑
void logic()
{
    //移动蛇身
    for (int i = snakeLength - 1; i > 0; i--)
    {
        snakeX[i] = snakeX[i - 1];
        snakeY[i] = snakeY[i - 1];
    }

    //根据方向移动蛇头
    switch (dir)
    {
    case LEFT:
        snakeX[0]--;
        break;
    case RIGHT:
        snakeX[0]++;
        break;
    case UP:
        snakeY[0]--;
        break;
    case DOWN:
        snakeY[0]++;
        break;
    }

    //判断是否吃到食物
    if (snakeX[0] == foodX && snakeY[0] == foodY)
    {
        score += 10;
        snakeLength++;
        foodX = rand() % width;
        foodY = rand() % height;
    }

    //判断是否撞墙或撞到自己
    if (snakeX[0] < 0 || snakeX[0] >= width || snakeY[0] < 0 || snakeY[0] >= height)
    {
        cout << "Game Over!" << endl;
        exit(0);
    }
    for (int i = 1; i < snakeLength; i++)
    {
        if (snakeX[i] == snakeX[0] && snakeY[i] == snakeY[0])
        {
            cout << "Game Over!" << endl;
            exit(0);
        }
    }
}

//主程序
int main()
{
    init();  //初始化游戏
    while (true)
    {
        draw();  //绘制游戏
        input();  //获取键盘输入
        logic();  //游戏逻辑
        Sleep(50);  //延时
    }
    return 0;
}

注意：这只是一个简单的实现，还有很多可以改进的地方，比如增加难度、增加音效、增加暂停功能等。