using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        /// Change these values:

        var boardSize = 10;

        var word = "CARROT";

        var rowIndex = 1;

        var columnIndex = 5;

        /// --------------------

​

        List<List<char?>> board = GetEmptyBoard(boardSize);

        // Display empty board

        board.Print();

​

        var wordWasPlacedHorizontally = board.AddWordHorizontally(word, rowIndex, columnIndex, boardSize);

        if (wordWasPlacedHorizontally)

        {

            // Display board with horizontally placed word

            board.Print();

        }

        // Start over with empty board

        board = GetEmptyBoard(boardSize);

        var wordWasPlacedVertically = board.AddWordVertically(word, rowIndex, columnIndex, boardSize);

        if (wordWasPlacedVertically)

        {

            // Display board with vertically placed word

            board.Print();

        }

    }

​

    private static List<List<char?>> GetEmptyBoard(int boardSize)

    {

        List<List<char?>> board = new();

        for (var rowIndex = 0; rowIndex < boardSize; rowIndex++)

        {

            var row = new List<char?>();

            for (var columnIndex = 0; columnIndex < boardSize; columnIndex++)

            {

                row.Add(null);

            }

            board.Add(row);

        }

        return board;

    }

}

​

public static class Helpers

{

    public static bool AddWordHorizontally(this List<List<char?>> board, string word, int rowIndex, int columnIndex, int boardSize)

    {

        Console.WriteLine();

        Console.WriteLine($"Trying to place {word} horizontally on the board...");

        // Make sure the provided word actually contains something

        if (string.IsNullOrWhiteSpace(word))

        {

            Console.WriteLine("Please provide an actual word.");

            return false;

        }

        var wordLength = word.Length;

        // Make sure the provided word fits on the board

        // Example: On a 10x10 board, the word 'COLLABORATION' will not fit, as it is 13 letters long

        if (wordLength > boardSize)

        {

            Console.WriteLine($"You cannot place a word that is longer than {boardSize} letters. '{word}' contains {wordLength} letters.");

            return false;

        }

        // Make sure the provided row index and column index are in fact ON the board

        // Example: On a 10x10 board, a row index of 10 or higher will be invalid

        if (rowIndex >= boardSize)

        {

            Console.WriteLine($"A row index of {rowIndex} is too large for this board! Please use a row index < {boardSize}.");

            return false;

        }

        if (columnIndex >= boardSize)

        {

            Console.WriteLine($"A column index of {columnIndex} is too large for this board! Please use a column index < {boardSize}.");

            return false;

        }

        var columnIndexOfFinalLetter = columnIndex + wordLength;

        // Make sure the provided column index (for placing the first letter of the word) allows for the WHOLE word to be placed on the board

        // Example: On a 10x10 board, if you want place the word 'DANCE' horizontally, starting at column index 7, you will only fit 'DAN' before reaching the end of the board

        if (columnIndexOfFinalLetter > boardSize)

        {

            Console.WriteLine($"{word} is too long to fit horizontally on the board when the first letter is put in column with index {columnIndex}.");

            return false;

        }

        // Place the word on the board

        for (var i = 0; i < wordLength; i++)

        {

            board[rowIndex][i + columnIndex] = word[i];

        }

        Console.WriteLine("Success!");

        return true;

    }

    public static bool AddWordVertically(this List<List<char?>> board, string word, int rowIndex, int columnIndex, int boardSize)

    {

        Console.WriteLine();

        Console.WriteLine($"Trying to place {word} vertically on the board...");

        // Make sure the provided word actually contains something

        if (string.IsNullOrWhiteSpace(word))

        {

            Console.WriteLine("Please provide an actual word.");

            return false;

        }

        var wordLength = word.Length;

        // Make sure the provided word fits on the board

        // Example: On a 10x10 board, the word 'COLLABORATION' will not fit, as it is 13 letters long

        if (wordLength > boardSize)

        {

            Console.WriteLine($"You cannot place a word that is longer than {boardSize} letters. '{word}' contains {wordLength} letters.");

            return false;

        }

        // Make sure the provided row index and column index are in fact ON the board

        // Example: On a 10x10 board, a row index of 10 or higher will be invalid

        if (rowIndex >= boardSize)

        {

            Console.WriteLine($"A row index of {rowIndex} is too large for this board! Please use a row index < {boardSize}.");

            return false;

        }

        if (columnIndex >= boardSize)

        {

            Console.WriteLine($"A column index of {columnIndex} is too large for this board! Please use a column index < {boardSize}.");

            return false;

        }

        // Make sure the provided row index (for placing the first letter of the word) allows for the WHOLE word to be placed on the board

        // Example: On a 10x10 board, if you want place the word 'DANCE' vertically, starting at row index 6, you will only fit 'DANC' before reaching the end of the board

        if (rowIndex + wordLength > boardSize)

        {

            Console.WriteLine($"{word} is too long to fit vertically on the board when the first letter is put in row with index {rowIndex}.");

            return false;

        }

        // Place the word on the board

        for (var i = 0; i < wordLength; i++)

        {

            board[i + rowIndex][columnIndex] = word[i];

        }

        Console.WriteLine("Success!");

        return true;

    }

    public static void Print(this List<List<char?>> matrix)

    {

        var boardBorder = "\n " + string.Concat(Enumerable.Repeat('-', 4 * matrix.Count - 1));

        Console.WriteLine(boardBorder);

        for (var rowIndex = 0; rowIndex < matrix.Count; rowIndex++)

        {

            Console.Write("| ");

            var row = matrix[rowIndex];

            foreach (var cellValue in row)

            {

                Console.Write(cellValue ?? ' ');

                Console.Write(" | ");

            }

            Console.Write(rowIndex);

            Console.WriteLine(boardBorder);

        }

        for (var i = 0; i < matrix.Count; i++)

        {

            Console.Write($"  {i} ");

        }

        Console.WriteLine();

    }

}

​