#include <graphics.h>	
#include <stdlib.h>	
#include <stdio.h>	
#include <conio.h>	
// this function initializes graphics mode	
// it will work only if you're using Borland C++ compiler & BGI drivers	
// if you're using another compiler you should overwrite body of this function	
void init_gr(void)	
{	
   /* request autodetection */	
   int gdriver = DETECT, gmode, errorcode;	
   /* initialize graphics mode */	
   initgraph(&gdriver, &gmode, "");	
   /* read result of initialization */	
   errorcode = graphresult();	
   if (errorcode != grOk)    /* an error occurred */	
   {	
      printf("Graphics error: %s\n", grapherrormsg(errorcode));	
      printf("Press any key to halt:");	
      getch();	
      exit(1);               /* return with error code */	
   }	
}	
// this function shuts graphics mode down	
// it will work only if you're using Borland C++ compiler & BGI drivers	
// if you're using another compiler you should overwrite body of this function	
void end_gr(void)	
{	
  closegraph();	
}	
// this function puts pixel on the screen in (x,y) position using color 'color'	
// it will work only if you're using Borland C++ compiler & BGI drivers	
// if you're using another compiler you should overwrite body of this function	
void PutPixel(int x, int y, int color)	
{	
  putpixel(x,y,color);	
}	
// this function gets color of pixel in (x,y) position	
// it will work only if you're using Borland C++ compiler & BGI drivers	
// if you're using another compiler you should overwrite body of this function	
int GetPixel(int x, int y)	
{	
  return getpixel(x,y);	
}	
// this function gets maximum horizontal coordinate	
// it will work only if you're using Borland C++ compiler & BGI drivers	
// if you're using another compiler you should overwrite body of this function	
int GetMaxX(void)	
{	
  return getmaxx();	
}	
// this function gets maximum vertical coordinate	
// it will work only if you're using Borland C++ compiler & BGI drivers	
// if you're using another compiler you should overwrite body of this function	
int GetMaxY(void)	
{	
  return getmaxy();	
}	
void FloodFill(int x, int y,int fill_color, int border_color)	
{	
  int x_left,x_right,YY,i;	
  int XMAX,YMAX;	
  XMAX=GetMaxX();	
  YMAX=GetMaxY();	
  // Light as many pixels as possible on line y	
  // and determine x_left and x_right	
  x_left=x_right=x;	
  while (GetPixel(x_left,y)!=border_color && x_left>0)	
  {	
     PutPixel(x_left,y,fill_color);	
     x_left--;	
  }	
  x_right++;	
  while (GetPixel(x_right,y)!=border_color && x_right<XMAX)	
  {	
     PutPixel(x_right,y,fill_color);	
     x_right++;	
  }	
  // Recursive calls of FloodFill for two remote points	
  x=(x_right+x_left)>>1; //shifting means division by 2	
  for(i=-1;i<=1;i+=2)	
  {	
     YY=y;	
     while (GetPixel(x,YY)!=border_color && YY<YMAX && YY>0) YY+=i;	
     YY=(y+YY)>>1;	
     if (GetPixel(x,YY)!=border_color && GetPixel(x,YY)!=fill_color) FloodFill(x,YY,fill_color,border_color);	
  }	
  // Recursive calls for all "dark" (not filled) pixels next	
  // to the line y (with x values between x_left and x_right	
  for(YY=y-1;YY<=y+1;YY+=2)	
  {	
    x=x_left+1;	
    while (x<x_right && YY>0 && YY<YMAX)	
    {	
      if (GetPixel(x,YY)!=border_color && GetPixel(x,YY)!=fill_color) FloodFill(x,YY,fill_color,border_color);	
      x++;	
    }	
  }	
}	
int main(void)	
{	
   // initializing graphics mode	
   init_gr();	
   // drawing area to fill	
   moveto(520,90); lineto(520,190); lineto(470,240);	
   lineto(520,290); lineto(520,390);	
   lineto(320,315); lineto(120,390);	
   lineto(120,290); lineto(170,240);	
   lineto(120,190); lineto(120, 90);	
   lineto(270,90); lineto(270,120);	
   lineto(170,120); lineto(170,150);	
   lineto(470,150); lineto(470,120);	
   lineto(370,120); lineto(370,90); lineto(520,90);	
   moveto(370,240); lineto(320,290); lineto(270,240);	
   lineto(320,190); lineto(370,240);	
   /* example */	
   FloodFill(121,91,1,15);	
   FloodFill(320,240,9,15);	
   FloodFill(100,20,3,15);	
   /* clean up */	
   getch();	
   end_gr();	
   return 0;	
}