贪吃蛇小游戏-----C语言实现

1.分析

　　众所周知，贪吃蛇游戏是一款经典的益智游戏，有PC和手机等多平台版本，既简单又耐玩。该游戏通过控制蛇头方向吃食物，从而使得蛇变得越来越长，蛇不能撞墙，也不能装到自己，否则游戏结束。玩过贪吃蛇的朋友都知道这个小游戏有一圈“墙”、还有食物以及蛇，还有吃了食物之后的分数。所以通过C语言实现贪吃蛇，可以分为以下几个模块来实现：

　　a)编程实现“墙”

　　b)实现随机食物的生成

　　c)蛇的构建

　　d)以上三部分都实现了之后，实现游戏运行的部分，包括蛇的移动、吃食物、判断是否撞墙或者撞到自己。

　　e)游戏结束时的相关操作

2.具体思路

　　要通过C语言实现贪吃蛇，首先就要用C语言将贪吃蛇的相关信息描述出来。C语言提供了结构体类型，我们可以用结构体描述蛇的结点（结点的横纵坐标）、运动状态、总分数、每个食物的分数等等。

　　首先实现进入游戏的"welcome"界面，为了将“欢迎来到贪吃蛇游戏”打印到屏幕的中间，可以运用库函数先设置窗口的大小（system("mode con cols=100 lines=30");将窗口设置为长100，宽30），再通过库函数中的GetStdHandle函数、SetConsoleCursorPosition函数（把光标定位到我们需要的位置）将这句话打印到屏幕中央。

　　其次可以通过相同的方法将光标固定到我们需要的位置，用特殊字符‘■’打印实现墙（注意，‘■’在c中占用两个字符，所以在设置循环条件时要格外注意）

　　接着通过编程实现蛇的移动，本文中蛇是通过单链表实现的，因此在实现蛇的移动时，如果蛇接下来走的位置（上下左右）为食物，将这个位置的用指针表示，可以将食物头插到用_psnake指针维护的蛇身中，如果接下来的位置不是食物，同样头插到蛇身中，再将蛇的最后一个结点打印时输出为空格字符，然后free最后一个节点。

3.代码如下

snake.h:

 #pragma once

 #include<Windows.h>
 #include<stdio.h>
 #include<time.h>
 #include<stdlib.h>

 #define WALL "■"
 #define FOOD "●"

 #define INIT_X 20
 #define INIT_Y 18
 typedef struct SnakeNode
 {
     int x;
     int y;
     struct SnakeNode *next;
 }SnakeNode, *pSnakeNode;

 //蛇的方向
 enum Diretion
 {
     UP,
     DOWN,
     LEFT,
     RIGHT
 };

 //状态
 enum GameState
 {
     OK,
     NORMAL_END,
     KILL_BY_WALL,
     KILL_BY_SELF
 };
 //游戏结构体
 typedef struct Snake
 {
     pSnakeNode _psnake;//维护蛇身的指针
     pSnakeNode _pFood;//维护食物的位置
     int _TotalScore;//总分数
     int _AddScore;//增加的分数
     int _SleepTime;//休眠时间
     enum Direction  _Dir;
     enum GameStatus _Status;
 }Snake, *pSnake;

 void GameStart(pSnake ps);
 void WelcomeToGame();//欢迎界面函数
 void SetPos(int x, int y);
 void CreateMap();//创建地图
 void InitSnake(pSnake ps);
 void CreateFood(pSnake ps);//创建食物
 void GameRun(pSnake ps);//运行游戏
 void pause();//暂停函数

 void snakmove(pSnake ps);
 int NextHasFood(pSnakeNode pn, pSnakeNode pf);//判断下个结点是否为食物
 void EatFood(pSnake ps,pSnakeNode pn);//吃食物
 void NoFood(pSnake ps, pSnakeNode pn);//没有食物
 void KillBYWALL(pSnake ps);
 void KillBySelf(pSnake ps);
 void GameEnd(pSnake ps);

snake.c:

 #include"snake.h"
 void  SetPos(int x, int y)
 {
     COORD pos = {  };
     HANDLE handle = GetStdHandle(STD_OUTPUT_HANDLE);
     pos.X = x; pos.Y = y;
     SetConsoleCursorPosition(handle, pos);//把光标定位到我们需要的位置了
 }
 void WelcomeToGame()//欢迎界面函数
 {
     //设置窗口大小
     system("mode con cols=100 lines=30");
     SetPos(, );//分装的函数用来定位光标
     printf("欢迎来到贪吃蛇小游戏\n");
     SetPos(, );
     system("pause");//暂停
     system("cls");//清空屏幕
     SetPos(, );
     printf("用↑，↓，←，→来控制蛇的移动，F1为加速，F2为减速\n");
     SetPos(, );
     printf("加速获得分数更多\n");
     SetPos(, );
     system("pause");
     system("cls");
 }

 void CreateMap()
 {
     int i = ;
     //上
     for (i = ; i <= ; i += )
     {
         SetPos(i, );
         printf(WALL);
     }
     //下
     for (i = ; i <= ; i += )
     {
         SetPos(i, );
         printf(WALL);
     }
     //左
     for (i = ; i <= ; i++)
     {
         SetPos(, i);
         printf(WALL);
     }
     //右
     for (i = ; i <= ; i++)
     {
         SetPos(, i);
         printf(WALL);
     }
 }
 pSnakeNode BuyNode()
 {
     pSnakeNode pRet = (pSnakeNode)malloc(sizeof(SnakeNode));
     if (pRet == NULL)
     {
         perror("BuyNode::malloc()");
         exit(EXIT_FAILURE);
     }
     pRet->x = ;
     pRet->y = ;
     pRet->next = NULL;
     return pRet;
 }
 void InitSnake(pSnake ps)
 {
     pSnakeNode first = BuyNode();//创建蛇头
     pSnakeNode cur = NULL;
     first->x = INIT_X;
     first->y = INIT_Y;
     int i = ;
     for (i = ; i <= ; i++)
     {
         cur = BuyNode();//创建蛇身
         cur->x = first->x + ;
         cur->y = first->y;
         cur->next = first;
         first = cur;
     }
     //打印蛇
     while (cur)
     {
         SetPos(cur->x, cur->y);
         printf(FOOD);
         cur = cur->next;
     }
     ps->_psnake = first;
 }

 void CreateFood(pSnake ps)
 {
     pSnakeNode pfood = BuyNode();
     pSnakeNode cur = ps->_psnake;
     pfood->y = rand() %  + ;
     do
     {
         pfood->x = rand() %  + ;//0-54,+2产生2-56
     } while (pfood->x %  != );
     while (cur)
     {
         if (cur->x == pfood->x&&cur->y == pfood->y)
         {
             CreateFood(ps);
         }
         cur = cur->next;
     }
     ps->_pFood = pfood;
     SetPos(pfood->x, pfood->y);
     printf(FOOD);
 }

 void GameStart(pSnake ps)
 {
     //打印欢迎界面
     WelcomeToGame();
     //创建地图，画墙
     CreateMap();
     //初始化蛇
     InitSnake(ps);
     //初始化食物
     CreateFood(ps);
     //游戏运行
     ps->_AddScore = ;//每次增加的分数
     ps->_TotalScore = ;//总分
     ps->_Dir = RIGHT;//方向
     ps->_SleepTime = ;//0.2秒
     ps->_Status = OK;//状态
 }

 void pause()//暂停函数
 {
     while ()
     {
         Sleep();
         if (GetAsyncKeyState(VK_SPACE))
         {
             return;
         }
     }
 }

 int NextHasFood(pSnakeNode pn, pSnakeNode pf)
 {
     return (pn->x == pf->x) && (pn->y == pf->y);
 }

 void EatFood(pSnake ps, pSnakeNode pn)//吃食物
 {
     pSnakeNode cur = NULL;
     pn->next = ps->_psnake;//头插
     ps->_psnake = pn;
     cur = ps->_psnake;
     ps->_TotalScore += ps->_AddScore;
     while (cur)
     {
         SetPos(cur->x, cur->y);
         printf(FOOD);
         cur = cur->next;
     }
     CreateFood(ps);
 }

 void NoFood(pSnake ps, pSnakeNode pn)//没有食物
 {
     pSnakeNode cur = NULL;
     pn->next = ps->_psnake;//头插
     ps->_psnake = pn;
     cur = ps->_psnake;
     while (cur->next->next)
     {
         SetPos(cur->x, cur->y);
         printf(FOOD);
         cur = cur->next;
     }
     SetPos(cur->x, cur->y);
     printf(FOOD);
     SetPos(cur->next->x, cur->next->y);
     printf(" ");
     free(cur->next);
     cur->next = NULL;
 }

 void snakmove(pSnake ps)//蛇的移动
 {
     pSnakeNode pNextNode = BuyNode();
     SetPos(, );
     printf("总分:%d", ps->_TotalScore);
     SetPos(, );
     printf("每个食物的得分：%d ", ps->_AddScore);
     //上
     switch (ps->_Dir)
     {
         case UP:
         {
             pNextNode->x = ps->_psnake->x;
             pNextNode->y = ps->_psnake->y - ;
             if (NextHasFood(pNextNode,ps->_pFood))
             {
                 //下一个节点是食物
                 EatFood(ps,pNextNode);
             }
             else
             {
                 NoFood(ps,pNextNode);
             }
             break;
         }
         case DOWN:
         {
             pNextNode->x = ps->_psnake->x;
             pNextNode->y = ps->_psnake->y + ;
             if (NextHasFood(pNextNode, ps->_pFood))
             {
               //下一个节点是食物
                   EatFood(ps, pNextNode);
               }
             else
             {
                   NoFood(ps, pNextNode);
             }
             break;
         }
         case LEFT:
         {
             pNextNode->x = ps->_psnake->x-;
             pNextNode->y = ps->_psnake->y;
             if (NextHasFood(pNextNode, ps->_pFood))
             {
                 //下一个节点是食物
                 EatFood(ps, pNextNode);
             }
             else
             {
                 NoFood(ps, pNextNode);
             }
             break;
         }
         case RIGHT:
         {
             pNextNode->x = ps->_psnake->x+;
             pNextNode->y = ps->_psnake->y ;
             if (NextHasFood(pNextNode, ps->_pFood))
             {
                  //下一个节点是食物
                 EatFood(ps, pNextNode);
             }
             else
             {
                 NoFood(ps, pNextNode);
             }
             break;
         }
         default:
         {
             break;
         }
     }
 }

 void KillBYWALL(pSnake ps)
 {
     if ((ps->_psnake->x == ) ||
         (ps->_psnake->x == ) ||
         (ps->_psnake->y == ) ||
         (ps->_psnake->y == ))
     {
         ps->_Status = KILL_BY_WALL;
     }
 }

 void KillBySelf(pSnake ps)
 {
     pSnakeNode tnext = ps->_psnake->next;
     while (tnext)
     {
         if ((tnext->x == ps->_psnake->x) && (tnext->y == ps->_psnake->y))
         {
             ps->_Status = KILL_BY_SELF;
             return;
         }
         tnext = tnext->next;
     }

 }
 void PrintHelpInfo()
 {
     SetPos(, );
     printf("用↑，↓，←，→来控制蛇的移动");
     SetPos(, );
     printf("F1为加速，F2为减速\n");
     SetPos(, );
     printf("加速获得分数更多\n");
     SetPos(, );
     printf("按空格暂停游戏\n");

 }

 void GameEnd(pSnake ps)
 {
     pSnakeNode cur = ps->_psnake;
     SetPos(, );
     if (ps->_Status == NORMAL_END)
     {
         SetPos(, );
         printf("游戏正常接结束\n");
         SetPos(, );
     }
     else if (ps->_Status == KILL_BY_SELF)
     {
         SetPos(, );
         printf("蛇撞到自己了\n");
         SetPos(, );
     }
     else if (ps->_Status == KILL_BY_WALL)
     {
         SetPos(, );
         printf("撞到墙了\n");
         SetPos(, );
     }
     while (cur)
     {
         pSnakeNode del = cur;
         cur = cur->next;
         free(del);
         del = NULL;
     }
     ps->_psnake = NULL;
     free(ps->_pFood);
     ps->_pFood = NULL;
 }

 void GameRun(pSnake ps)
 {
     PrintHelpInfo();
     do
     {
         //确定方向
         if (GetAsyncKeyState(VK_UP)&&(ps->_Dir!=DOWN))
         {
             ps->_Dir = UP;
         }
         else if (GetAsyncKeyState(VK_DOWN) && ps->_Dir != UP)
         {
             ps->_Dir = DOWN;
         }
         else if (GetAsyncKeyState(VK_LEFT) && ps->_Dir != RIGHT)
         {
             ps->_Dir = LEFT;
         }
         else if (GetAsyncKeyState(VK_RIGHT) && ps->_Dir != LEFT)
         {
             ps->_Dir = RIGHT;
         }
         else if (GetAsyncKeyState(VK_SPACE))
         {
             //暂停游戏
             pause();
         }
         else if (GetAsyncKeyState(VK_ESCAPE))
         {
             //结束游戏
             ps->_Status = NORMAL_END;
             break;
         }
         else if (GetAsyncKeyState(VK_F1))
         {
             //加速
             if (ps->_SleepTime >= )
             {
                 ps->_SleepTime -= ;
                 ps->_AddScore += ;
             }
         }
         else if (GetAsyncKeyState(VK_F2))
         {
             //减速
             if (ps->_SleepTime <= )
             {
                 ps->_SleepTime += ;
                 ps->_AddScore -= ;
             }
             if (ps->_SleepTime > )
             {
                 ps->_AddScore = ;//不能一直减
             }
         }
         Sleep(ps->_SleepTime);//睡眠
         //蛇的移动
         snakmove(ps);
         KillBYWALL(ps);
         KillBySelf(ps);
     } while (ps->_Status == OK);
 }

test.c:

 #include"snake.h"

 void test()
 {
     srand((unsigned)time(NULL));
     Snake snake = {  };//创建贪吃蛇
     GameStart(&snake);
     GameRun(&snake);
     GameEnd(&snake);
 }

 int main()
 {
     test();
     system("pause");
     return ;
 }