#include<graphics.h> #include<conio.h> #include<stdio.h> #include<stdlib.h> #include<dos.h> #include<bios.h> #include<math.h> #define ESC 0x11b0 #define R 8

out()

{

int key;

key=bioskey(0);

if(key==ESC)

exit(0);

}

void initgr(void) /*初始化 */ { int gd=DETECT,gm=0; initgraph(&gd,&gm,""); }

void main(void)

{

int minx=40;

int miny=40;

int maxx=400;

int maxy=400;

int x,y;

int cx,cy;

int addx=1,addy=-1;

x=(minx+maxx)/2;

y=(miny+maxy)/2; initgr(); rectangle(40,40,400,400);

while(1)

{

cx=x,cy=y;

x=x+addx,y=addy+y;

if(x<=minx+R+1||x>=maxx-R-1)

addx=-addx;

if(y<=miny+R+1||y>=maxy-R-1)

addy=-addy;

setcolor(WHITE);

circle(cx,cy,R);

delay(6000);

setcolor(RED);

circle(x,y,R);

if(bioskey(1))

out();

}

}