using System;

public class Program

{

    public static void Main()

    {

        // http://msdn.microsoft.com/en-us/library/9b9dty7d.aspx

        int[][] matrix = new int[][]{

            new int[]{1,2,3},

            new int[]{4,5,6},

            new int[]{7,8,9}

        };

        Console.WriteLine("Displaying matrix: ");

        DisplayMatrix(matrix);

        Console.WriteLine("Displaying diagonals: ");        

        DisplayDiagonals(matrix);

        Console.WriteLine("Displaying reversed matrix: ");

        int[][] reveredMatrix = ReverseMatrix(matrix);

    }

    // Should display matrix as it is declaed in the code

        // 1,2,3

        // 4,5,6

        // 7,8,9

    private static void DisplayMatrix(int[][] matrix)

    {       

        foreach (int[] i in matrix)

        {

            Console.WriteLine(String.Join(",", i));

        }               

    }

        // 1   3

        //   5

        // 7   9

    private static void DisplayDiagonals(int[][] matrix)

    {

        for (int i = 0; i < matrix.Length; i++)

        {

            for (int j = 0; j < matrix[i].Length; j++)

            {

                    if(matrix[i][j]% 2 == 0) //KK: It can be simplified to i == j

                    {

                        Console.Write(" ");

                    }else 

                    {   

                        Console.Write(String.Join(",", matrix[i][j]));          

                    }

            }

            Console.WriteLine();

        }

    }

    // should return the following

        // 9,8,7

        // 6,5,4

        // 3,2,1

    private static int[][] ReverseMatrix(int[][] matrix)

    {

        for (int i = matrix.Length-1; i >= 0; i--)

        {

            for (int j = matrix[i].Length-1; j >= 0; j--)

            {

                Console.Write(matrix[i][j] + " ");

            }

            Console.WriteLine();

        }

        return matrix;

    }

}