#define DEPTH 100 // iterations depth	
#include <graphics.h>	
#include <stdlib.h>	
#include <stdio.h>	
#include <conio.h>	
#include <math.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);	
}	
void Mandelbrot(void)	
{	
  float zi, zr, ci, cr, tmp;	
  // assuming graphics mode 640x480 16 colors	
  for(int i=-320;i<320;i++)  // for all pixels on the X axe	
  {	
     ci=((float)i)/320.0; // setting Im c = i/320	
     for(int j=-380;j<160;j++)  // for all pixels on the Y axe	
     {	
        cr=((float)j)/240.0; // setting Re c = j/240	
        zi=zr=0.0; // fixing z=0 we'll change c - it's Mandelbrot set	
        for(int k=0;k<DEPTH;k++)	
        {	
   // z=z*z+c	
   //(zr+i*zi)*(zr+i*zi)=(zr*zr-zi*zi)+i*(2*zr*zi)	
   // zi=zr*zr-zi*zi+cr	
   //	
   tmp=zr*zr-zi*zi;	
   zi=2*zr*zi+ci;	
   zr=tmp+cr;	
   if (zr*zr+zi*zi>1.0E16) break; // break if |z| is very big	
    }	
    if (k<DEPTH)	
   PutPixel(i+320,j+380,k%3+1); // z was very big => it is external point	
    else PutPixel(i+320,j+380,11); // internal point	
     }	
     if(kbhit()) break;	
  }	
}	
int main(void)	
{	
  // initializing graphics mode	
  init_gr();	
  /* example */	
  Mandelbrot();	
  /* clean up */	
  getch();	
  end_gr();	
  return 0;	
}