using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        int[][] sudoku = {

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

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

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

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

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

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

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

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

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

        };

​

        int[][] goodSudoku2 = {

            new int[] {1,4, 2,3},

            new int[] {3,2, 4,1},

​

            new int[] {4,1, 3,2},

            new int[] {2,3, 1,4}

        };

​

        int[][] badSudoku1 =  {

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

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

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

​

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

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

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

​

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

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

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

                    };

​

        int[][] badSudoku2 = {

                        new int[] {1,2,3,4,5},

                        new int[] {1,2,3,4},

                        new int[] {1,2,3,4},

                        new int[] {1}

                    };

​

        try

        {

            CheckSudoku(sudoku);

            CheckSudoku(goodSudoku2);

            CheckSudoku(badSudoku1);

            CheckSudoku(badSudoku2);

        }

        catch (Exception ex)

        {

            Console.Write(ex);

        }

    }

​

    public static int GetLength(int[][] sudoku)

    {

        try

        {

            var length = sudoku.Count();

            if (Array.Exists(sudoku, row => row.Count() != length)) throw new Exception();

​

            return length;

        }

        catch

        {

            return -1;

        }

    }

​

    public static bool CheckLengthValid(int length)

    {

        try

        {

            if (length < 0) throw new Exception();

            var sqrt = Math.Sqrt(length);

            return sqrt == (int)sqrt;

        }

        catch

        {

            return false;

        }

    }

​

    public static int[][] GetColumns(int length, int[][] values)

    {

        List<int[]> columns = new List<int[]>();

        for (int i = 0; i < length; i++)

        {

            columns.Add(Enumerable.Range(1, length).ToArray());

        }

​

        for (int i = 0; i < length; i++)

        {

            for (int j = 0; j < length; j++)

            {

                columns[i][j] = values[j][i];

            }

        }

​

        return columns.ToArray();

    }

​

    public static int[][] GetLittleSquares(int length, int[][] values)

    {

        List<int[]> littleSquares = new List<int[]>();

        var sqrt = (int)Math.Sqrt(length);

​

        for (int i = 0; i < length; i = i + 1)

        {

            int littleSquareRow = (int)(i / sqrt) * sqrt;

            int littleSquareColumn = (int)(i % sqrt) * sqrt;

​

            List<int> littleSquare = new List<int>();

            for (int j = 0; j < sqrt; j++)

            {

                for (int k = 0; k < sqrt; k++)

                {

                    littleSquare.Add(values[littleSquareRow + j][littleSquareColumn + k]);

                }

            }

​

            littleSquares.Add(littleSquare.ToArray());

        }

​

        return littleSquares.ToArray();

    }

​

    public static bool CheckContainsAllNumbers(int length, int[] values)

    {

        try

        {

            int[] numbers = Enumerable.Range(1, length).ToArray();

            if (Array.Exists(numbers, number => !values.Contains(number))) throw new Exception();

​

            return true;

        }

        catch

        {

            return false;

        }

    }

​

    public static bool CheckSudoku(int[][] sudoku)

    {

        try

        {

            int length = GetLength(sudoku);

            bool isLengthValid = CheckLengthValid(length);

            if (!isLengthValid) throw new Exception("Invalid Length");

​

            var rows = sudoku;

            var columns = GetColumns(length, sudoku);

            var littleSquares = GetLittleSquares(length, sudoku);

​

            var isRowsInvalid = Array.Exists(rows, row => !CheckContainsAllNumbers(length, row));

            if (isRowsInvalid) throw new Exception("Theres invalid row(s)");

​

            var isColumnsInvalid = Array.Exists(columns, column => !CheckContainsAllNumbers(length, column));

            if (isColumnsInvalid) throw new Exception("Theres invalid column(s)");

​

            var isLittleSquaresInvalid = Array.Exists(littleSquares, littleSquare => !CheckContainsAllNumbers(length, littleSquare));

            if (isLittleSquaresInvalid) throw new Exception("Theres invalid little square(s)");

​

            Console.WriteLine(true);

            return true;

        }

        catch (Exception ex)

        {

            Console.WriteLine(false);

            Console.WriteLine(ex.Message);

            return false;

        }

    }

}