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

#define U 1
#define D 2
#define L 3 
#define R 4    //蛇的狀態(tài)，U：上 ；D：下；L:左 R：右

typedef struct SNAKE //蛇身的一個節(jié)點
{
  int x;
  int y;
  struct SNAKE *next;
}snake;

//全局變量//
int score = 0, add = 10;//總得分與每次吃食物得分。
int status, sleeptime = 200;//每次運行的時間間隔
snake *head, *food;//蛇頭指針，食物指針
snake *q;//遍歷蛇的時候用到的指針
int endGamestatus = 0; //游戲結(jié)束的情況，1：撞到墻；2：咬到自己；3：主動退出游戲。

//聲明全部函數(shù)//
void Pos();
void creatMap();
void initSnake();
int biteSelf();
void createFood();
void cantCrossWall();
void snakeMove();
void pause();
void runGame();
void initGame();
void endGame();
void gameStart();

void Pos(int x, int y)//設(shè)置光標(biāo)位置
{
  COORD pos;
  HANDLE hOutput;
  pos.X = x;
  pos.Y = y;
  hOutput = GetStdHandle(STD_OUTPUT_HANDLE);//返回標(biāo)準(zhǔn)的輸入、輸出或錯誤的設(shè)備的句柄，也就是獲得輸入、輸出/錯誤的屏幕緩沖區(qū)的句柄
  SetConsoleCursorPosition(hOutput, pos);
}

void creatMap()//創(chuàng)建地圖
{
  int i;
  for (i = 0; i<58; i += 2)//打印上下邊框
  {
    Pos(i, 0);
    printf("■");//一個方塊占兩個位置
    Pos(i, 26);
    printf("■");
  }
  for (i = 1; i<26; i++)//打印左右邊框
  {
    Pos(0, i);
    printf("■");
    Pos(56, i);
    printf("■");
  }
}

void initSnake()//初始化蛇身
{
  snake *tail;
  int i;
  tail = (snake*)malloc(sizeof(snake));//從蛇尾開始，頭插法，以x,y設(shè)定開始的位置//
  tail->x = 24;
  tail->y = 5;
  tail->next = NULL;
  for (i = 1; i <= 4; i++)//初始長度為4
  {
    head = (snake*)malloc(sizeof(snake));
    head->next = tail;
    head->x = 24 + 2 * i;
    head->y = 5;
    tail = head;
  }
  while (tail != NULL)//從頭到為，輸出蛇身
  {
    Pos(tail->x, tail->y);
    printf("■");
    tail = tail->next;
  }
}
//??
int biteSelf()//判斷是否咬到了自己
{
  snake *self;
  self = head->next;
  while (self != NULL)
  {
    if (self->x == head->x && self->y == head->y)
    {
      return 1;
    } 
    self = self->next;
  }
  return 0;
}

void createFood()//隨機出現(xiàn)食物
{
  snake *food_1;
  srand((unsigned)time(NULL));//為了防止每次產(chǎn)生的隨機數(shù)相同，種子設(shè)置為time
  food_1 = (snake*)malloc(sizeof(snake));
  while ((food_1->x % 2) != 0)  //保證其為偶數(shù)，使得食物能與蛇頭對其
  {
    food_1->x = rand() % 52 + 2;
  }
  food_1->y = rand() % 24 + 1;
  q = head;
  while (q->next == NULL)
  {
    if (q->x == food_1->x && q->y == food_1->y) //判斷蛇身是否與食物重合
    {
      free(food_1);
      createFood();
    }
    q = q->next;
  }
  Pos(food_1->x, food_1->y);
  food = food_1;
  printf("■");
}

void cantCrossWall()//不能穿墻
{
  if (head->x == 0 || head->x == 56 || head->y == 0 || head->y == 26)
  {
    endGamestatus = 1;
    endGame();
  }
}

void snakeMove()//蛇前進,上U,下D,左L,右R
{
  snake * nexthead;
  cantCrossWall();

  nexthead = (snake*)malloc(sizeof(snake));
  if (status == U)
  {
    nexthead->x = head->x;
    nexthead->y = head->y - 1;
    if (nexthead->x == food->x && nexthead->y == food->y)//如果下一個有食物//
    {
      nexthead->next = head;
      head = nexthead;
      q = head;
      while (q != NULL)
      {
        Pos(q->x, q->y);
        printf("■");
        q = q->next;
      }
      score = score + add;
      createFood();
    }
    else                        //如果沒有食物//
    {
      nexthead->next = head;
      head = nexthead;
      q = head;
      while (q->next->next != NULL)
      {
        Pos(q->x, q->y);
        printf("■");
        q = q->next;
      }
      Pos(q->next->x, q->next->y);
      printf(" ");
      free(q->next);
      q->next = NULL;
    }
  }
  if (status == D)
  {
    nexthead->x = head->x;
    nexthead->y = head->y + 1;
    if (nexthead->x == food->x && nexthead->y == food->y) //有食物
    {
      nexthead->next = head;
      head = nexthead;
      q = head;
      while (q != NULL)
      {
        Pos(q->x, q->y);
        printf("■");
        q = q->next;
      }
      score = score + add;
      createFood();
    }
    else                //沒有食物
    {
      nexthead->next = head;
      head = nexthead;
      q = head;
      while (q->next->next != NULL)
      {
        Pos(q->x, q->y);
        printf("■");
        q = q->next;
      }
      Pos(q->next->x, q->next->y);
      printf(" ");
      free(q->next);
      q->next = NULL;
    }
  }
  if (status == L)
  {
    nexthead->x = head->x - 2;
    nexthead->y = head->y;
    if (nexthead->x == food->x && nexthead->y == food->y)//有食物
    {
      nexthead->next = head;
      head = nexthead;
      q = head;
      while (q != NULL)
      {
        Pos(q->x, q->y);
        printf("■");
        q = q->next;
      }
      score = score + add;
      createFood();
    }
    else                //沒有食物
    {
      nexthead->next = head;
      head = nexthead;
      q = head;
      while (q->next->next != NULL)
      {
        Pos(q->x, q->y);
        printf("■");
        q = q->next;
      }
      Pos(q->next->x, q->next->y);
      printf(" ");
      free(q->next);
      q->next = NULL;
    }
  }
  if (status == R)
  {
    nexthead->x = head->x + 2;
    nexthead->y = head->y;
    if (nexthead->x == food->x && nexthead->y == food->y)//有食物
    {
      nexthead->next = head;
      head = nexthead;
      q = head;
      while (q != NULL)
      {
        Pos(q->x, q->y);
        printf("■");
        q = q->next;
      }
      score = score + add;
      createFood();
    }
    else                     //沒有食物
    {
      nexthead->next = head;
      head = nexthead;
      q = head;
      while (q->next->next != NULL)
      {
        Pos(q->x, q->y);
        printf("■");
        q = q->next;
      }
      Pos(q->next->x, q->next->y);
      printf(" ");
      free(q->next);
      q->next = NULL;
    }
  }
  if (biteSelf() == 1)    //判斷是否會咬到自己
  {
    endGamestatus = 2;
    endGame();
  }
}

void pause()//暫停
{
  while (1)
  {
    Sleep(300);
    if (GetAsyncKeyState(VK_SPACE))
    {
      break;
    }

  }
}

void runGame()//控制游戲    
{

  Pos(64, 15);
  printf("不能穿墻，不能咬到自己\n");
  Pos(64, 16);
  printf("用↑.↓.←.→分別控制蛇的移動.");
  Pos(64, 17);
  printf("F1 為加速，F(xiàn)2 為減速\n");
  Pos(64, 18);
  printf("ESC ：退出游戲.space：暫停游戲.");
  Pos(64, 20);
  printf("C語言研究中心 www.clang.cc");
  status = R;
  while (1)
  {
    Pos(64, 10);
    printf("得分：%d ", score);
    Pos(64, 11);
    printf("每個食物得分：%d分", add);
    if (GetAsyncKeyState(VK_UP) && status != D)
    {
      status = U;
    }
    else if (GetAsyncKeyState(VK_DOWN) && status != U)
    {
      status = D;
    }
    else if (GetAsyncKeyState(VK_LEFT) && status != R)
    {
      status = L;
    }
    else if (GetAsyncKeyState(VK_RIGHT) && status != L)
    {
      status = R;
    }
    else if (GetAsyncKeyState(VK_SPACE))
    {
      pause();
    }
    else if (GetAsyncKeyState(VK_ESCAPE))
    {
      endGamestatus = 3;
      break;
    }
    else if (GetAsyncKeyState(VK_F1))
    {
      if (sleeptime >= 50)
      {
        sleeptime = sleeptime - 30;
        add = add + 2;
        if (sleeptime == 320)
        {
          add = 2;//防止減到1之后再加回來有錯
        }
      }
    }
    else if (GetAsyncKeyState(VK_F2))
    {
      if (sleeptime<350)
      {
        sleeptime = sleeptime + 30;
        add = add - 2;
        if (sleeptime == 350)
        {
          add = 1; //保證最低分為1
        }
      }
    }
    Sleep(sleeptime);
    snakeMove();
  }
}

void initGame()//開始界面
{
  Pos(40, 12);

  system("title C語言研究中心  www.clang.cc");
  printf("歡迎來到貪食蛇游戲！");
  Pos(40, 25);
  printf("       C語言研究中心 www.clang.cc.\n");
  system("pause");
  system("cls");
  Pos(25, 12);
  printf("用↑.↓.←.→分別控制蛇的移動， F1 為加速，2 為減速\n");
  Pos(25, 13);
  printf("加速將能得到更高的分?jǐn)?shù)。\n");
  system("pause");
  system("cls");
}

void endGame()//結(jié)束游戲
{

  system("cls");
  Pos(24, 12);
  if (endGamestatus == 1)
  {
    printf("對不起，您撞到墻了。游戲結(jié)束.");
  }
  else if (endGamestatus == 2)
  {
    printf("對不起，您咬到自己了。游戲結(jié)束.");
  }
  else if (endGamestatus == 3)
  {
    printf("您的已經(jīng)結(jié)束了游戲。");
  }
  Pos(24, 13);
  printf("您的得分是%d\n", score);
  while (getchar() != 'y')
  {  
    printf("close?[y]");
  }
  exit(0);
}

void gameStart()//游戲初始化
{
  system("mode con cols=100 lines=30");
  initGame();
  creatMap();
  initSnake();
  createFood();
}

int main()
{
  gameStart();
  runGame();
  endGame();
  return 0;
}