Train animation in C++

Program:

# include <iostream.h>
# include <stdio.h>
# include <graphics.h>
# include <math.h>
# include <conio.h>
# include <dos.h>

void main()
{
 clrscr();
 int gdriver = DETECT, gmode, errorcode;
 initgraph(&gdriver, &gmode, "c:\\tc\\bgi");
 int i,yc=400;
 for(i=100;i>=-400;i=i-2)
 {
  //Engine
  rectangle(425+i,370,515+i,400);
  circle(450+i,yc,10);
  circle(490+i,yc,10);

  rectangle(470+i,350,515+i,370); //Driver's cabin
  rectangle(440+i,362,450+i,370); //Smoke pipe

  setcolor(BLACK);
  line(470+i,370,515+i,370);
  setcolor(WHITE);

  //First car
  rectangle(535+i,350,625+i,400);
  circle(560+i,yc,10);
  circle(600+i,yc,10);

  line(515+i,382,535+i,382);     //Connector between engine and car....
  line(0,410,700,410); //track
  delay(10);

  //Compromising for line in between wheels...
  setcolor(BLACK);
  line(440+i,yc,460+i,yc);
  line(480+i,yc,500+i,yc);
  line(550+i,yc,570+i,yc);
  line(590+i,yc,610+i,yc);
  setcolor(WHITE);

  clearviewport();
 }
 getch();
}

Output: