Circle using Mid-Point Algorithm

#include<graphics.h> 
#include<conio.h> 
#include<stdio.h> 

void plotpoints(int x,int y,int cx,int cy) 
{ 
    putpixel(cx+x,cy+y,4); 
    putpixel(cx-x,cy+y,4); 
    putpixel(cx+x,cy-y,4); 
    putpixel(cx-x,cy-y,4); 
    putpixel(cx+y,cy+x,4); 
    putpixel(cx-y,cy+x,4); 
    putpixel(cx+y,cy-x,4); 
    putpixel(cx-y,cy-x,4); 
} 

void main() 
{ 
    int cx,cy,x=0,y,r,p; 
    int gd=DETECT,gm=DETECT; 

    clrscr(); 

    printf("Enter the center n"); 
    scanf("%d%d",&cx,&cy); 
    printf("Enter the radius : "); 
    scanf("%d",&r); 

    y=r; 
    p=1-r; 

    initgraph(&gd,&gm,""); 
    cleardevice(); 

    while(x<y) 
    { 
        plotpoints(x,y,cx,cy); 
        x++; 
        if(p<0) 
            p+=2*x+1; 
        else 
        { 
            y--; 
            p+=2*(x-y)+1; 
        } 
    } 

    getch(); 

}