점 찍기

package programmers;

public class 점_찍기 {

   public static long solution(int k, int d) {
      long answer = 0;

      for (int x = 0; x <= d; x += k) {
         long nx = (long)Math.pow(x, 2);
         long nd = (long)Math.pow(d, 2);
         int result = (int)Math.sqrt(nd - nx);
         answer += (result / k) + 1;
      }

      return answer;
   }

   public static void main(String[] args) {
      System.out.println(solution(2, 4));
      System.out.println(solution(1, 5));
   }
}