point-Inside,outside,or-on-circle.c

#include <stdio.h>
int main()
{
  int x, y, x0, y0, r, f;
  printf("\nEnter x0,y0,r : ");
  scanf("%d%d%d", &x0, &y0, &r);
  printf("\nEnter x,y :");
  scanf("%d%d", &x, &y);
  f = (x - x0) * (x - x0) + (y - y0) * (y - y0) - r * r;
  if (f == 0)
    printf("It is on circle.\n");
  else if (f > 0)
    printf("It is out of circle.\n");
  else
    printf("It is in circle.n");
  getch();
  return (0);
}