using System;

public class Program

{

    public static void Main()

    {

        int[][] board1 = new int[][]

        {

            new int[] {5, 3, 4, 6, 7, 8, 9, 1, 2},

            new int[] {6, 7, 2, 1, 9, 5, 3, 4, 8},

            new int[] {1, 9, 8, 3, 4, 2, 5, 6, 7},

            new int[] {8, 5, 9, 7, 6, 1, 4, 2, 3},

            new int[] {4, 2, 6, 8, 5, 3, 7, 9, 1},

            new int[] {7, 1, 3, 9, 2, 4, 8, 5, 6},

            new int[] {9, 6, 1, 5, 3, 7, 2, 8, 4},

            new int[] {2, 8, 7, 4, 1, 9, 6, 3, 5},

            new int[] {3, 4, 5, 2, 8, 6, 1, 7, 9}

        };

        int[][] board2= new int[][]

        {

            new int[] {1, 2, 3, 4, 5, 6, 7, 8, 9},

            new int[] {2, 3, 1, 5, 6, 4, 8, 9, 7},

            new int[] {3, 1, 2, 6, 4, 5, 9, 7, 8},

            new int[] {4, 5, 6, 7, 8, 9, 1, 2, 3},

            new int[] {5, 6, 4, 8, 9, 7, 2, 3, 1},

            new int[] {6, 4, 5, 9, 7, 8, 3, 1, 2},

            new int[] {7, 8, 9, 1, 2, 3, 4, 5, 6},

            new int[] {8, 9, 7, 2, 3, 1, 5, 6, 4},

            new int[] {9, 7, 8, 3, 1, 2, 6, 4, 5}

        };

        Console.WriteLine("Hello World\n");

        Boolean yay = new Boolean();

        Boolean yay2 = new Boolean();

        yay = Sudoku.ValidateSolution(board1);

        yay = Sudoku.ValidateSolution(board1);

        Console.WriteLine("Board 1 is ... " + (yay ? "Good!" : "Bad!"));

        Console.WriteLine("\n-------Next Board-------\n");

        Console.WriteLine("Board 2 is ... " + (yay2 ? "Good!" : "Bad!"));

    }

}

​

public class Sudoku

{

    public static bool ValidateSolution(int[][] board)

    {

        Console.WriteLine("\n-------- Start New Board --------\n");

        // Should probably have a sanity check for empty arrays, values, etc...

        int[] row = new int[board.Length + 1];

        int[,] column = new int[board.Length, board.Length + 1];

        int[,] lilSquare = new int[board.Length, board.Length + 1];

        // Setup a loop set for iterating over coords (x,y) using top left x=0, y=0

        for (int y = 0; y < board.Length; y++)

        {

            Console.WriteLine("---- Next Row ----");

            for (int x = 0; x < board.Length; x++)

            {

                // Figure out which lilSquare we're on

                int square = findLilSquare(x,y);

                // Increment values based on number existence

                lilSquare[square, board[y][x]] += 1;

                row[board[y][x]] += 1;

                column[x, board[y][x]] += 1;

                // Board Checks

                Console.Write("Location X:" + x + ", Y:" + y + "  Board-value / Row-array index:" + (board[y][x]) + "  Row value:" + row[board[y][x]]);

                Console.WriteLine("  Square: " + square + "  Column: " + y + "  Value " + board[y][x] + "  Count: " + column[x, board[y][x]]);

                if (row[board[y][x]] > 1)

                {

                    return false;

                }

                if (column[x, board[y][x]] > 1)

                {

                      return false;

                }

                if (lilSquare[square, board[y][x]] > 1)

                {

                      return false;

                }                               

                // reset our row array, since it is only one level deep

                if (x == board.Length - 1)

                {

                    row = new int[board.Length + 1];

                }

            }// end x loop

        }// end y loop

        return true;      

    }// end ValidateSolution

    public static int findLilSquare(int x, int y) // Squares are 0-8, not 1-9, starting at top left

    {

        // Little squares 0-2

        if (0 <= y && y <= 2)

        {

            return (x/3) + 0;

        }

        // Little squares 3-5

        if (3 <= y && y <= 5)

        {

            return (x/3) + 3;

        }

        // Little squares 6-8

        if (6 <= y && y <= 8)

        {

            return (x/3) + 6;

        }

        else

        {

            return -1; // This could make things very bad...

        }

    }

}