帮我写一个贪吃蛇的代码并运行

由于您没有说明具体语言，我将以Python为例，为您提供一个简单的贪吃蛇代码。

import pygame
import random

# 定义颜色
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)

# 初始化pygame
pygame.init()

# 设置屏幕大小
SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600
screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))

# 设置字体
font = pygame.font.SysFont(None, 48)

# 设置贪吃蛇初始位置
snake_position = [100, 50]
snake_body = [[100, 50], [90, 50], [80, 50]]

# 设置食物初始位置
food_position = [random.randrange(1, (SCREEN_WIDTH // 10)) * 10, 
                 random.randrange(1, (SCREEN_HEIGHT // 10)) * 10]
food_spawn = True

# 设置初始方向
direction = "RIGHT"
change_to = direction

# 设置游戏结束标志
game_over = False

# 定义游戏主循环
while not game_over:
    # 处理事件
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            game_over = True
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_RIGHT:
                change_to = "RIGHT"
            elif event.key == pygame.K_LEFT:
                change_to = "LEFT"
            elif event.key == pygame.K_UP:
                change_to = "UP"
            elif event.key == pygame.K_DOWN:
                change_to = "DOWN"

    # 确定方向
    if change_to == "RIGHT" and direction != "LEFT":
        direction = "RIGHT"
    elif change_to == "LEFT" and direction != "RIGHT":
        direction = "LEFT"
    elif change_to == "UP" and direction != "DOWN":
        direction = "UP"
    elif change_to == "DOWN" and direction != "UP":
        direction = "DOWN"

    # 移动贪吃蛇
    if direction == "RIGHT":
        snake_position[0] += 10
    elif direction == "LEFT":
        snake_position[0] -= 10
    elif direction == "UP":
        snake_position[1] -= 10
    elif direction == "DOWN":
        snake_position[1] += 10

    # 更新贪吃蛇
    snake_body.insert(0, list(snake_position))
    if snake_position == food_position:
        food_spawn = False
    else:
        snake_body.pop()

    # 生成食物
    if not food_spawn:
        food_position = [random.randrange(1, (SCREEN_WIDTH // 10)) * 10, 
                         random.randrange(1, (SCREEN_HEIGHT // 10)) * 10]
    food_spawn = True

    # 绘制屏幕
    screen.fill(BLACK)
    for position in snake_body:
        pygame.draw.rect(screen, GREEN, pygame.Rect(
            position[0], position[1], 10, 10))
    pygame.draw.rect(screen, BLUE, pygame.Rect(
        food_position[0], food_position[1], 10, 10))

    # 判断游戏结束
    if snake_position[0] < 0 or snake_position[0] > SCREEN_WIDTH-10:
        game_over = True
    elif snake_position[1] < 0 or snake_position[1] > SCREEN_HEIGHT-10:
        game_over = True
    for block in snake_body[1:]:
        if snake_position == block:
            game_over = True

    # 更新屏幕
    pygame.display.update()

    # 设置游戏帧率
    fps = pygame.time.Clock()
    fps.tick(15)

# 显示游戏结束信息
text = font.render("Game Over", True, RED)
screen.blit(text, [SCREEN_WIDTH/2-100, SCREEN_HEIGHT/2-50])
pygame.display.update()

# 关闭pygame
pygame.quit()

您可以将此代码保存为一个.py文件，然后在命令行中运行。当您运行该代码时，将会看到贪吃蛇游戏窗口。您可以通过键盘上的方向键来控制贪吃蛇的移动方向。当贪吃蛇碰到边界或自己时，游戏将会结束，并显示"Game Over"字样。