//贪吃蛇游戏的程序框架（很久以前的程序框架了拿出来一起看看）

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

#define HENG 80
#define SHU 25  //HENG是宽度，SHU是高度
#define TIME 400 //初始速度

void Gotoxy(int x, int y);//光标
void Food(struct SHE *head);//food食物
int Move(struct SHE *head);//用于蛇的移动
int Panduan(struct SHE *head, int x, int y);//用于食物与失败条件的判断
struct SHE *Link(struct SHE *head);//蛇身增长
void FreeShe(struct SHE *head);//释放内存
void Gameover(void);//游戏失败画面，如果窗口大小不是80*25导致画面不协调可舍去
void Huitu(struct SHE *head);//绘图

int Fx, Fy;  //食物的位置
int fen;   //得分
int fang; //方向参数
int Tx, Ty;

//构造蛇身
struct SHE
{
    int x;
    int y;
    struct SHE *next;
};

int main(void)
{
    struct SHE *head = NULL;
    int temp;
    int times = TIME;
    char m;

    do
    {
        fen = 0;
        fang = 2;
        temp = fen;
        times = TIME;
        head = NULL;

        head = (struct SHE *)malloc(sizeof(struct SHE));
        head -> x = 40;
        head -> y = 13;
        head -> next = NULL;

        Food(head);

        while (1)
        {
            Huitu(head);
            Sleep(times);
            if (0 == Move(head))
            {
                FreeShe(head);
                Gameover();
                break;
            }
            if (temp < fen)
            {
                Food(head);
                temp = fen;
                if (times > 50)
                {
                    times -=10;
                }
                else if (times > 20)
                {
                    times -=1;
                }
                else
                    ;
            }
        }

        do
        {
            Gotoxy(19,21);
            printf("是否继续？Y/N:");
            scanf(" %c", &m);
            system("cls");//清屏
        } while (m != 'Y' && m != 'y' && m != 'n' && m != 'N');
    } while (m == 'Y' || m == 'y');

    return 0;
}

//绘图
void Huitu(struct SHE *head)
{
    int flag = 1;

    while (head != NULL)
    {
        Gotoxy(head -> x, head -> y);
        if (flag == 1)
        {
            printf("□");
        }
        else if (flag == 2)
        {
            printf("■");
        }
        else
            ;
        Gotoxy(Tx, Ty);
        printf(" ");
        flag++;
        head = head -> next;
    }
}

//用于光标的移动
void Gotoxy(int x, int y)
{ 
  COORD coord; 
  coord.X = x; 
  coord.Y = y; 
  SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), coord);
}

//食物位置构造
void Food(struct SHE *head)
{
    int flag = 0;
    struct SHE *pr = head;

    do
    {
        srand(GetTickCount()); //基于毫秒级的随机数产生办法，需头文件winbase.h, windows中设计程序可以用windows.h
        Fx = (rand()%40) * 2;
        Fy = (rand()%12) * 2;
        flag = 0;
        pr = head;
        while (pr != NULL) //防止食物位置与蛇形重合
        {
            if (pr -> x == Fx && pr -> y == Fy)
            {
                flag = 1;
                break;
            }
            pr = pr -> next;
        }
    } while (flag == 1);
    Gotoxy(Fx, Fy);
    printf("■");
}

//用于蛇的移动
int Move(struct SHE *head)
{
    char op;
    int tox, toy, flag, temp;

    if (kbhit())  //kbhit函数用于检查当前是否有键盘输入，若有则返回一个非0值，否则返回0，需头文件conio.h
    {
        op = getch();
        switch (op)
        {
            case 'w':
                if (fang != 3)
                fang = 1;
                break;
            case 'd':
                if (fang != 4)
                fang = 2;
                break;
            case 's':
                if (fang != 1)
                fang = 3;
                break;
            case 'a':
                if (fang != 2)
                fang = 4;
                break;
            default:
                break;
        }
    }

    switch (fang)
    {
        case 1:
            toy = (head -> y) - 1;
            tox = (head -> x);
            break;
        case 2:
            tox = (head -> x) + 2;
            toy = (head -> y);
            break;
        case 3:
            toy = (head -> y) + 1;
            tox = (head -> x);
            break;
        case 4:
            tox = (head -> x) - 2;
            toy = (head -> y);
            break;
        default:
            break;
    }
    flag = Panduan(head, tox, toy);
    if (flag == 0)
    {
        return 0; //game over
    }
    else if (flag == 1)
    {
        head = Link(head);
        fen++;
    }
    else
    {
        ;
    }
    while (head != NULL)
    {
        temp = head -> x;
        head -> x = tox;
        tox = temp;

        temp = head -> y;
        head -> y = toy;
        toy = temp;

        head = head -> next;
    }
    return 1;
}

//用于食物与失败条件的判断
int Panduan(struct SHE *head, int x, int y)
{

    int flag = 1;

    if (x < 0 || x > HENG - 1 || y < 0 || y > SHU - 1)
    {
        return 0;  //撞墙
    }
    while (head != NULL)
    {
        if (head -> x == x && head -> y == y && flag != 1)
        {
            return 0; //咬到自己
        }
        flag++;
        if (head -> next == NULL)
        {
            Tx = head -> x;
            Ty = head -> y;
        }
        head = head -> next;
    }
    if (x == Fx && y == Fy)
    {
        return 1;//有食物
    }
    return 2;//无异常
}

//蛇身增长
struct SHE *Link(struct SHE *head)
{
    struct SHE *p, *pr;

    pr = head;//指针指向链的头head
    p = (struct SHE *)malloc(sizeof(struct SHE));//申请内存，创建新的节点
    if (p == NULL)
    {
        printf("发生错误！！！");
        exit(0);
    }
    if (head == NULL)//如果链是空的，新节点就是链的头
    {
        head = p;
    }
    else
    {
        while (pr -> next != NULL)
        {
            pr = pr -> next;//循环语句，将指针pr移到链的末尾
        }
        pr -> next = p;//新节点加到链的末尾
    }
    p -> x = Tx;////给新节点赋值
    p -> y = Ty;
    p -> next = NULL;///p->next 指向下一个元素，就相当于下一个元素的指针，指向空值，表示是尾。
    return head;
}

//释放内存
void FreeShe(struct SHE *head)
{
    struct SHE *pr = NULL;

    while (head != NULL)
    {
        pr = head;
        head = head -> next;
        free(pr);
    }
}

//游戏失败画面，如果窗口大小不是80*25导致画面不协调可舍去
void Gameover(void)
{
    int i,j;

    int a[SHU][HENG]={插入你想要的内容！}};

    Gotoxy(0, 0);
    for (i = 0; i < SHU; i++)
    {
        for (j = 0; j< HENG; j++)
        {
            if (a[i][j] == 0)
            {
                printf(" ");
            }
            else
            {
                printf("0");
            }
        }
    }

    Gotoxy(19, 20);
    printf("游戏最终得分是 %d 分！！！\n", fen);
}