Mid-Point Circle program in C

#include<conio.h>
#include<stdio.h>
#include<graphics.h>
void main()
{
int xc, yc, x=0, y, i=0, gd=DETECT, gm, p[20];
clrscr();
initgraph(&gd, &gm, "c:\\tc\\bgi");
printf("enter the center of the circle : ");
scanf("%d",&xc);
scanf("%d",&yc);
printf("enter the radius : ");
scanf("%d",&y);
p[0]=1-y;
putpixel(xc+x,yc+y,100);
putpixel(xc+x,yc-y,100);
putpixel(xc+y,yc+x,100);
putpixel(xc+y,yc-x,100);
putpixel(xc-x,yc+y,100);
putpixel(xc-x,yc-y,100);
putpixel(xc-y,yc+x,100);
putpixel(xc-y,yc-x,100);



while(x<=y)
{
if(p[i]<0)
{
p[i+1]=p[i]+2*x+1;
x=x+1;
i++;
}
else
{
p[i+1]=p[i]+2*x-2*y+1;
x=x+1;
y=y-1;
i++;
}
putpixel(xc+x,yc+y,100);
putpixel(xc-x,yc+y,100);
putpixel(xc+x,yc-y,100);
putpixel(xc-x,yc-y,100);
putpixel(xc+y,yc+x,100);
putpixel(xc+y,yc-x,100);
putpixel(xc-y,yc+x,100);
putpixel(xc-y,yc-x,100);
}
getch();
closegraph();
}