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

 void show_screen( );

 void draw_pattern(constint,constint,constint,constint);

 void Circle(constint,constint,constint);
 void Line(constint,constint,constint,constint);

 int main( )
    {
       int driver=VGA;
       int mode=VGAHI;

       int x=0;
       int y=0;
       int r=0;

       int n=0;

       do
      {
         show_screen( );

         gotoxy(8,10);
         cout<<"Center of the Circle :";

         gotoxy(8,11);
         cout<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ";

         gotoxy(12,13);
         cout<<"Enter the value of x = ";
         cin>>x;

         gotoxy(12,14);
         cout<<"Enter the value of y = ";
         cin>>y;

         gotoxy(8,18);
         cout<<"Radius of the Circle :";

         gotoxy(8,19);
         cout<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ";

         gotoxy(12,21);
         cout<<"Enter the value of r = ";
         cin>>r;

         gotoxy(8,25);
         cout<<"Number of Points on the Circle :";

         gotoxy(8,26);
         cout<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ";

         gotoxy(12,28);
         cout<<"Enter the value of n (n>=2) = ";
         cin>>n;

         initgraph(&driver,&mode,"..\\Bgi");

         setcolor(15);
           draw_pattern(x,y,r,n);

         setcolor(15);
           outtextxy(110,460,"Press <Enter> to continue or any other key to exit.");

         int key=int(getch( ));

         if(key!=13)
        break;
      }
       while(1);

       return 0;
    }

 /*************************************************************************///--------------------------  draw_pattern( )  --------------------------///*************************************************************************/void draw_pattern(constint x,constint y,constint r, constint n)
    {
       Circle(x,y,r);

       float x_1=0;
       float y_1=0;

       float x_2=0;
       float y_2=0;

       for(int count_1=0;count_1<n;count_1++)
      {
         x_1=(x+(r*cos((2*M_PI*count_1)/n)));
         y_1=(y+(r*sin((2*M_PI*count_1)/n)));

         for(int count_2=0;count_2<n;count_2++)
        {
           x_2=x+(r*cos((2*M_PI*count_2)/n));
           y_2=y+(r*sin((2*M_PI*count_2)/n));

           Line((int)(x_1+0.5),(int)(y_1+0.5),
                          (int)(x_2+0.5),(int)(y_2+0.5));
        }
      }
    }

 /*************************************************************************///-----------------------------  Circle( )  -----------------------------///*************************************************************************/void Circle(constint h,constint k,constint r)
    {
       int color=getcolor( );

       int x=0;
       int y=r;
       int p=(1-r);

       do
      {
         putpixel((h+x),(k+y),color);
         putpixel((h+y),(k+x),color);
         putpixel((h+y),(k-x),color);
         putpixel((h+x),(k-y),color);
         putpixel((h-x),(k-y),color);
         putpixel((h-y),(k-x),color);
         putpixel((h-y),(k+x),color);
         putpixel((h-x),(k+y),color);

         x++;

         if(p<0)
        p+=((2*x)+1);

         else
        {
           y--;
           p+=((2*(x-y))+1);
        }
      }
       while(x<=y);
    }

 /*************************************************************************///-------------------------------  Line( )  -----------------------------///*************************************************************************/void Line(constint x_1,constint y_1,constint x_2,constint y_2)
    {
       int color=getcolor( );

       int x1=x_1;
       int y1=y_1;

       int x2=x_2;
       int y2=y_2;

       if(x_1>x_2)
      {
         x1=x_2;
         y1=y_2;

         x2=x_1;
         y2=y_1;
      }

       int dx=abs(x2-x1);
       int dy=abs(y2-y1);
       int inc_dec=((y2>=y1)?1:-1);

       if(dx>dy)
      {
         int two_dy=(2*dy);
         int two_dy_dx=(2*(dy-dx));
         int p=((2*dy)-dx);

         int x=x1;
         int y=y1;

         putpixel(x,y,color);

         while(x<x2)
        {
           x++;

           if(p<0)
              p+=two_dy;

           else
              {
             y+=inc_dec;
             p+=two_dy_dx;
              }

           putpixel(x,y,color);
        }
      }

       else
      {
         int two_dx=(2*dx);
         int two_dx_dy=(2*(dx-dy));
         int p=((2*dx)-dy);

         int x=x1;
         int y=y1;

         putpixel(x,y,color);

         while(y!=y2)
        {
           y+=inc_dec;

           if(p<0)
              p+=two_dx;

           else
              {
             x++;
             p+=two_dx_dy;
              }

           putpixel(x,y,color);
        }
      }
    }

 /*************************************************************************///--------------------------  show_screen( )  ---------------------------///*************************************************************************/void show_screen( )
    {
       restorecrtmode( );
       textmode(C4350);

       cprintf("\n********************************************************************************");
       cprintf("**************************-                           -*************************");
       cprintf("*-------------------------- ");

       textbackground(1);
       cprintf(" N-Points Circle Pattern ");
       textbackground(8);

       cprintf(" -------------------------*");
       cprintf("**************************-                           -*************************");
       cprintf("*-****************************************************************************-*");

       for(int count=0;count<42;count++)
      cprintf("*-*                                                                          *-*");

       gotoxy(1,46);
       cprintf("*-****************************************************************************-*");
       cprintf("*------------------------------------------------------------------------------*");
       cprintf("********************************************************************************");

       gotoxy(1,2);
    }