beijing

 #include<stdio.h>
 #include<string.h>
 #include<stdlib.h>
 #include<graphics.h>
 #include<conio.h>
 #include<math.h>
 #include<dos.h>
 int init;
 int read_mouse;
 void cursor;
 void newxy;
 int main()
 {
     int buttons,x,y;
     char str[];
     int driver=VCA;
     int moede=VGAHT;
     initgraph(&gdriver,&mode,"");
     cleardevice();
     rectangle(,,,);
     setfillstyle(,);
     circle(,,);
     x=,y=;
     cursor(x,y);
     for(;;)
     {

         newxy(&x,&y,&butttons);
         if(x>=&&x<=&&y>=&&y<=&&buttons)
         {
             cleardevice();
             closegraph();
             exit();
         }
     }
 }
 void(int x,int y)
 {

     int x1,x2,y1,y2;
     x1=x-;
     x2=x+;
     y1=y-;
     y2=y+;
     line(x1,y,x2,y);
     line(x,y1,x,y2);
 }
 int read_mouse(int*mx,int*my,int*mbutton)
 {
     union REGS regs;
     int x0=*mx,y0=*my,button0=*mbutton;
     int xnew,ynew;
     do
     {
         regs.x.ax=;
         int86(0x33,&regs,&regs);
         xnew=regs.x.cx;
         ynew=regs.x.dx;
         *mbutton=regs.x.bx;
     }
     while(xnew==x0&&ynew==y0&&*mbutton==button0);
     *mx=xnew;
     *my=ynew;
     switch(*mbutton)
     {

     case :
         return ;
     case :
         return ;
     case :
         return ;
     case :
         return3;
     default :
         return4;
     }
 }
 void newxy(int *mx,int *my,int *mbutt)
 {

   int ch,xx0=*mx,yy0=*my;
   int xm,ym;
   ch=read_mouse(&xm,&ym,mbutt);
   curse(xx0,yy0);
   curse(xm,xy);
   switch(ch)
   {

       case : break;
       case : cirse(xm,ym,);break;
       case : rectangle(xm-,ym-,xm+,ym+);break;
       default : putpixel(xm,ym,);break;
   }
     *mx=xm;
     *my=ym;
 }