#include <Conio.h>

#include <graphics.h>

#include <stdlib.h>

#define closegr closegraph

#define NDOT 4





typedef struct

{

   int a,b,x,y;

} DotInf;





void initgr(void) /* BGI初始化 */

{

  int gd = DETECT, gm = 0;

  registerbgidriver(EGAVGA_driver);

  initgraph(&gd, &gm, "");

}



void delta(DotInf dot,int c)

{

   int i,j;

   setcolor(c);

     for (i=0;i<NDOT;i++)

       for (j=i+1;j<NDOT;j++) line(dot.x,dot.y,dot.x,dot.y);

}



int main(void)

{

  int i,j,whi=0;

  DotInf snk,everdot;



  initgr(); /* BGI初始化 */



  for (i=0;i<NDOT;i++) {

   snk.a=snk.b=snk.x=snk.y=200;

  }

  delta(snk,2);

  randomize();

  while (!kbhit())

  {

    if (whi<4) whi++; else whi=0;

    for (i=0;i<600;i++) delay(10);



    delta(everdot,0);

    delta(snk,2);



    for (i=0;i<NDOT;i++){

      if ((snk.x==snk.a)&&(snk.y==snk.b)){

         snk.a=rand()%600+1;

         snk.b=rand()%400+20;

      }

    }

    for (i=0;i<NDOT;i++){

    everdot.x=snk.x;

    everdot.y=snk.y;

    if (whi>i) continue;

       if (snk.x>snk.a)

         snk.x--;

       else if (snk.x<snk.a)

         snk.x++;

       else

       {

           if (snk.y>snk.b)

             snk.y--;

           else if (snk.y<snk.b)

             snk.y++;

       }

    }





  }



  getch();

  closegr(); /* 恢复TEXT屏幕模式 */

  return 0;

}