Adv2018/D11.2/Program.cs

using System;

namespace D11._2
{
    class Program
    {
        static void Main(string[] args)
        {
            if (args.Length == 0) return;
            int serial = int.Parse(args[0]);

            const int length = 300;
            var grid = new int[length, length];

            for (int x = 1; x <= length; ++x)
            {
                for (int y = 1; y <= length; ++y)
                {
                    int id = (x + 10);

                    int n = (id * y + serial) * id;
                    int c = (n / 100) % 10;


                    grid[x - 1, y - 1] = c - 5;
                }
            }

            int maxTotal = 0;
            (int x, int y, int g)? maxCoordinates = null;

            for (var g = 0; g < length; ++g)
            {
                for (int x = 1; x <= length -g + 1; ++x)
                    for (int y = 1; y <= length -g + 1; ++y)
                    {
                        
                        int total = 0;
                        for (int j = 0; j < g; ++j)
                            for (int i = 0; i < g; ++i)
                            {
                                total += grid[x - 1 + i, y - 1 + j];
                            }

                        if (total > maxTotal)
                        {
                            maxTotal = total;
                            maxCoordinates = (x, y, g);
                        }
                    }
            }

            Console.WriteLine($"The answer is : ({maxCoordinates.Value.x},{maxCoordinates.Value.y},{maxCoordinates.Value.g})");
        }
    }
}