Matrix1

using System;
class Program
{
    static void Main(string[] args)
    {
        int n = int.Parse(Console.ReadLine());
        char type = char.Parse(Console.ReadLine());
        var arr = new int[n, n];
        switch (type)
        {
            case 'a': printA(arr); break;
            case 'b': printB(arr); break;
            case 'c': printC(arr); break;
            case 'd': printD(arr); break;
        }

        for (int i = 0; i < n; i++)
        {
            for (int j = 0; j < n; j++) Console.Write(arr[i, j]+(j+1<n?" ":""));
            Console.WriteLine();
        }
    }

    static void printA(int[,] arr)
    {
        int counter = 1;
        for (int i = 0; i < arr.GetLength(0); i++)
        {
            for (int j = 0; j < arr.GetLength(1); j++) arr[j, i] = counter++;
        }
    }

    static void printB(int[,] arr)
    {
        int counter = 1;
        for (int i = 0; i < arr.GetLength(0); i++)
        {
            for (int j = 0; j < arr.GetLength(1); j++)
            {
                if (i % 2 == 0) arr[j, i] = counter++;
                else { arr[arr.GetLength(1) -1 - j, i] = counter++; }
            }
        }
    }

    static void printC(int[,] arr)
    {
        int number = arr.GetLength(0), counter = 1;
        for (int i = number-1, x = 1; i >= 0; i--, x++)
        {
            for (int j = 0; j < x; j++)
            {
                arr[i+j, j] = counter++;
            }
        }
        for (int i = 1; i < number; i++)
        {
            for (int j = 0; j+i < number; j++)
            {
                arr[j, i+j] = counter++;
            }
        }
    }

    static void printD(int[,] matrix)
    {
        int x = 0, y = 0, direction = 2, counter = 1;
        int number = matrix.GetLength(0);

        while (matrix[y, x] == 0)
        {
            matrix[y, x] = counter++;
            switch (direction)
            {
                case 2:
                    if (y + 1 < number && matrix[y+1, x] == 0) y++;
                    else { direction = 1; x++; };
                    break;
                case 1:
                    if (x + 1 < number && matrix[y, x+1] == 0) x++;
                    else { direction = 3; y--; };
                    break;
                case 4:
                    if (x - 1 >= 0 && matrix[y, x - 1] == 0) x--;
                    else { direction = 2; y++; };
                    break;
                case 3:
                    if (y - 1 >= 0 && matrix[y - 1, x] == 0) y--;
                    else { direction = 4; x--; };
                    break;
            }
        }
    }
}