/*07. * Write a program that finds the largest area of equal neighbor elements
in a rectangular matrix and prints its size. Hint: you can use the algorithm
"Depth-first search" or "Breadth-first search" (find them in Wikipedia).*/

using System;

class FindsLargestAreaOfEqualElements
{
    static void Main()
    {
        string[,] field = {{"c", "b", "d", "j", "a", "a"},
                           {"b", "a", "j", "c", "z", "a"},
                           {"l", "a", "a", "j", "a", "a"},
                           {"j", "a", "j", "a", "a", "l"},
                           {"b", "a", "a", "a", "z", "a"}};

        int tempLength = 0;
        bool[,] temp = new bool[field.GetLength(0), field.GetLength(1)];
        int maxLength = 1;
        bool[,] largestArea = new bool[field.GetLength(0), field.GetLength(1)];

        for (int row = 0; row < field.GetLength(0); row++)
        {
            for ( int col = 0; col < field.GetLength(1); col++)
            {
                DepthFirstSearch(field, row, col, ref temp, ref tempLength);

                 if (tempLength > maxLength)
                {
                    maxLength = tempLength;

                    for (int i = 0; i < temp.GetLength(0); i++)
                    {
                        for (int j = 0; j < temp.GetLength(1); j++)
                        {
                            largestArea[i, j] = temp[i, j];
                        }
                    }
                }

                tempLength = 0;
                temp = new bool[field.GetLength(0), field.GetLength(1)];
            }
        }

        for (int row = 0; row < field.GetLength(0); row++)
        {
            for (int col = 0; col < field.GetLength(1); col++)
            {
                if (largestArea[row, col])
                {
                    Console.ForegroundColor = ConsoleColor.Green;
                    Console.Write(field[row, col] + " ");
                    Console.ForegroundColor = ConsoleColor.Gray;
                }
                else
                {
                    Console.Write(field[row, col] + " ");
                }
            }
            Console.WriteLine();
        }
    }

    static void DepthFirstSearch(string[,] array, int row, int col, ref bool[,] temp, ref int tempLength)
    {
        temp[row, col] = true;
        tempLength += 1;
        for ( int r = row - 1; r <= row + 1; r++)
        {
            for (int c = col - 1; c <= col + 1; c++)
            {
                if (c < 0)
                {
                    c++;
                }
                if (c > array.GetLength(1) - 1)
                {
                    continue;
                }
                if (r < 0)
                {
                    r++;
                }
                if (r > array.GetLength(0) - 1)
                {
                    continue;
                }

                if (array[row, col] == array[r, c] && !temp[r, c])
                {
                    temp[r, c] = true;

                    DepthFirstSearch(array, r ,c, ref temp, ref tempLength);
                }
            }
        }
    }
}