Exam 9. Disk

namespace _03.Disk
{
    using System;

    class Disk
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            int radius = int.Parse(Console.ReadLine());

            int diskCenter = n / 2;
            for (int row = 0; row < n; row++)
            {
                for (int col = 0; col < n; col++)
                {
                    Console.Write(IsDiskPart(row, col, diskCenter, radius) ? "*" : ".");
                }

                Console.WriteLine();
            }

            Console.WriteLine();
        }

        private static bool IsDiskPart(int row, int col, int diskCenter, int radius)
        {
            int x = col - diskCenter;
            int y = row - diskCenter;

            double distanceFromCenter = Math.Sqrt((x * x) + (y * y));
            return distanceFromCenter <= radius;
        }
    }
}