程序代码：

#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <string.h>
#include <windows.h>
#include <time.h>
#include <math.h>

#define H 25
#define W 40
void map();
int move(struct snake * p);
void key(char key, int * direction);

struct snake//蛇的结构体
{
    int * x, * y;
    int joint;//蛇的长度
    int direction;//蛇的方向
    int life;
}play;

void gotoxy(int x, int y)
{
    COORD c;
    c.X = 2 * x, c.Y = y; //本游戏只使用双字节符号
    SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), c);
}

void main()
{

    int i,j;
    struct snake * p;
    p=(struct snake *)malloc(sizeof(struct snake));
    p->x=(int *)malloc(sizeof(int));
    p->y=(int *)malloc(sizeof(int));

    p->x[0] = 15;
    p->y[0] = 12;

    p->x[1] = 15;
    p->y[1] = 13;

    p->x[2] = 15;
    p->y[2] = 14;

    p->x[3] = 15;
    p->y[3] = 15;
    p->direction=1;
    p->joint=4;
    printf("%d %d %d %d ",p->x[0],p->y[0],p->direction);
    char ch;
    while(1)
    {
        if(kbhit())
        {
            ch = getch();
            key(ch,&p->direction);
            p->joint++;//在这里我想测试下蛇的长度是否会增加
        }
        move(p);
        Sleep(200);

    }
    getch();
}

void key(char key, int * direction)
{
    if(key == 'w'&& (*direction)!=2)
        (*direction)=1;
    else if(key == 's'&& (*direction)!=1)
        (*direction)=2;
    else if(key == 'a'&& (*direction)!=4)
        (*direction)=3;
    else if(key == 'd'&& (*direction)!=3)
        (*direction)=4;
}

int move(struct snake * p)
{
    int i;
    int food = 0;
    if(p->direction == 1)
        p->y[0]=p->y[0]-1;
    else if(p->direction == 2)
        p->y[0]=p->y[0]+1;
    else if(p->direction == 3)
        p->x[0]=p->x[0]-1;
    else if(p->direction == 4)
        p->x[0]=p->x[0]+1;
    
    p->x[p->joint] = p->x[p->joint-1];
    p->y[p->joint] = p->y[p->joint-1];
    gotoxy(p->x[p->joint],p->y[p->joint]);
    printf("  ");
    for(i = (p->joint-1);i > 0;--i)
    {
        p->x[i] = p->x[i-1];
        p->y[i] = p->y[i-1];
    }
    gotoxy(p->x[i],p->y[i]);
    printf("■");            
    return 0;
}