#include <stdio.h>
#include <conio.h>
#include <graphics.h>
void main()
{
 int gd=DETECT;
 int gm=DETECT;
 int dx,dy,Xa,Ya,Xb,Yb,c,r,p,f;
 detectgraph(&gm, &gd);
 initgraph(&gm,&gd,"c:\\tc\\bgi");
 cleardevice();
 printf("\n\n\n\n\t\t\tEnter your first X-coordinates: ");
 scanf("%d",&Xa);
 printf("\t\t\tEnter your first Y-coordinates: ");
 scanf("%d",&Ya);
 printf("\t\t\tEnter your second X-coordinates: ");
 scanf("%d",&Xb);
 printf("\t\t\tEnter your second Y-coordinates: ");
 scanf("%d",&Yb);
 printf("\n\n\n\n\n\t\t\t\t      WAIT!");
 dx=Xb-Xa;
 dy=Yb-Ya;
 p=2*dy+dx;
 if(Xa<Xb)
 {
   c=Xa;
   r=Ya;
   f=Xb;
 }
 else
 {
  c=Xb;
  r=Yb;
  f=Xa;
 }
 putpixel(c,r,YELLOW);
 do
 {
   c=c+1;
   if(p>0)
    p=p+2*dy;
   else
   {
    r=r-1;
    p=p+2*(dy+dx);
   }
   putpixel(c,r,YELLOW);
 }
 while(c<=f);
 getch();
 line(Xa,Ya,Xb,Yb);
 getch();
 }