C++简单项目--贪吃蛇

在800*600的地图上，蛇的初始长度为3节，用数组记录每一节的位置（每个正方形左上角的坐标），每一节为长度为10的正方形，初始方向向右。随机生成30个障碍物的的位置，随机生成食物的位置。吃到食物之后（即蛇头与食物位置相同），蛇的长度增加一节，每次移动时将数组的每一个元素向后移一位，第一位根据方向改变坐标。这样最后一位坐标在没吃到食物时会移到无法表现出来的位置，也可以用于吃到食物时的增长。

移动之后判断是否碰到障碍物或出界或咬到自身，用窗口命令提示游戏结束，并跳出死循环，程序结束。

#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<graphics.h>
#include<time.h>
#include<conio.h>
using namespace std;
struct point{
    int x,y;
}obstacle[];
struct {
    int num;
    struct point xy[];
    int dir;
}snake;
struct {
    struct point xy;
    int flag;

}food;
void drawsnake() {
    int i;
    for (i = ; i < snake.num; i++) {
        setlinecolor(BLACK);
        setfillcolor(RGB((rand() % ), (rand() % ), (rand() % )));
        fillrectangle(snake.xy[i].x, snake.xy[i].y, snake.xy[i].x + , snake.xy[i].y + );
    }
}
void movesnake() {
    int i = snake.num;
    for (; i > ; i--) {
        snake.xy[i].x = snake.xy[i - ].x;
        snake.xy[i].y = snake.xy[i - ].y;
    }
    switch (snake.dir) {
    case :snake.xy[].y -= ;
        break;
    case :snake.xy[].y += ;
        break;
    case :snake.xy[].x -= ;
        break;
    case :snake.xy[].x += ;
        break;
    }
}
bool check() {
    int i;
    for (i = ; i < snake.num; i++) {
        if (snake.xy[].x == snake.xy[i].x&&snake.xy[].y == snake.xy[i].y) {
            return false;
        }
    }
    if (snake.xy[].x <  || snake.xy[].y <  || snake.xy[].y> || snake.xy[].x>) {
        return false;
    }
    for (i = ; i < ; i++) {
        if (snake.xy[].x == obstacle[i].x&&snake.xy[].y == obstacle[i].y) {
            return false;
        }
    }
}
void keyDown() {
    char ch = '\0';
    ch = _getch();
    switch (ch) {
    case 'd':
    case 'D':
        if (snake.dir != ) {
            snake.dir = ;
        }
        break;
    case 'w':
    case 'W':
        if (snake.dir != ) {
            snake.dir = ;
        }
        break;
    case 'a':
    case 'A':
        if (snake.dir != ) {
            snake.dir = ;
        }
        break;
    case 's':
    case 'S':
        if (snake.dir != ) {
            snake.dir = ;
        }
        break;
    default:
        break;
    }
}
void drawob() {
    int i;
    setlinecolor(BLACK);
    setfillcolor(BLACK);
    for (i = ; i < ; i++) {
        fillrectangle(obstacle[i].x, obstacle[i].y, obstacle[i].x + , obstacle[i].y + );
    }
}
int main() {
    srand((unsigned int)time());
    HWND hwnd=initgraph(, );
    setbkcolor(RGB(, , ));
    cleardevice();
    snake.num = ;
    snake.xy[].x = ;
    snake.xy[].x = ;
    snake.xy[].x = ;
    snake.xy[].y = ;
    snake.xy[].y = ;
    snake.xy[].y = ;
    snake.dir = ;
    food.flag = ;
    int i;

    for (i = ; i < ; i++) {
        obstacle[i].x = rand() %  *  + ;
        obstacle[i].y = rand() %  *  + ;

    }
    drawsnake();
    while () {
        if (food.flag == ) {
            food.flag = ;
            food.xy.x = rand() %  * ;
            food.xy.y = rand() %  * ;
        }
        movesnake();
        if (snake.xy[].x == food.xy.x&& snake.xy[].y == food.xy.y) {
            food.flag = ;
            snake.num++;
        }
        if (check() == false) {
            MessageBox(hwnd, "Gameover","Game over!",);
            break;
        }
        cleardevice();
        setlinecolor(BLACK);
        setfillcolor(WHITE);
        fillrectangle(food.xy.x, food.xy.y, food.xy.x + , food.xy.y + );
        drawsnake();
        drawob();
        char text[];
        settextcolor(BLACK);
        outtextxy(, , "WASD控制");
        sprintf(text, "num=%d", snake.num);
        outtextxy(, , text);
        while (_kbhit() ){
            keyDown();
        }
        Sleep();
    }
    //system("pause");
    return ;
}