1实现弹跳小球

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

void main(){
    int i, j;
    int x = 0; 
    int y = 5;
    
    int velocity_x = 1;
    int velocity_y = 1;
    int left = 0;
    int right = 20;
    int top = 0;
    int bottom = 10;
    
    while(1){
        x += velocity_x;
        y += velocity_y;
        
        system("cls");            //清屏函数，在stdlib.h中
        for(i = 0; i < y; i++)    //输出小球前面的空行和空格    
            printf("\n");
        for(j = 0; j < x; j++)
            printf(" ");
        printf("o");            //输出小球
        printf("\n");
        Sleep(50);        //等待若干毫秒，控制小球弹跳的速度，windows.harderr
        
        if((y <= top) || (y >= bottom)){
            velocity_y = -velocity_y;
            printf("\a");        //碰到边界，实现响铃
        }
        if((x <= left) || (x >= right)){
            velocity_x = -velocity_x;
            printf("\a");
        }
    }
}