using System;
using System.Collections.Generic;

namespace P27.LargestAreaOfEqualNumbers
{
    class Program
    {
        static void Main(string[] args)
        {
            int[,] matrix =
            {
                { 1, 0, 1, 1, 1, 1 },
                { 0, 3, 3, 1, 4, 1 },
                { 1, 3, 1, 1, 3, 1 },
                { 1, 3, 1, 3, 3, 1 },
                { 1, 3, 3, 3, 3, 1 }
            };
            Console.WriteLine(FindLargestArreaOfEqualElements(matrix));
        }


        private static int FindLargestArreaOfEqualElements(int[,] pMatrix)
        {
            int result = 0;
            int bestResult = 0;
            for (int row = 0; row < pMatrix.GetLength(0); row++)
            {
                for (int col = 0; col < pMatrix.GetLength(1); col++)
                {
                    if (pMatrix[row, col] != int.MinValue)
                    {
                        result = FindArreaOfEqualElements(pMatrix, row, col, pMatrix[row, col]);
                        if (result > bestResult)
                        {
                            bestResult = result;
                        }
                    }
                }
            }
            return bestResult;
        }

        private static int FindArreaOfEqualElements(int[,] pMatrix ,int row,int col, int value)
        {
            int result = 0;
            Queue<Point2D> visitedPointsQueue = new Queue<Point2D>();
            visitedPointsQueue.Enqueue(new Point2D(row,col));
            while (visitedPointsQueue.Count > 0)
            {
                Point2D currentPoint = visitedPointsQueue.Dequeue();
                if(pMatrix[currentPoint.X,currentPoint.Y] == value)
                {
                    result++;
                }
                pMatrix[currentPoint.X, currentPoint.Y] = int.MinValue;
                if (currentPoint.X > 0 && pMatrix[currentPoint.X-1,currentPoint.Y] == value)
                {
                    visitedPointsQueue.Enqueue(new Point2D(currentPoint.X-1, currentPoint.Y));
                }
                if (currentPoint.X < pMatrix.GetLength(0) - 1 && pMatrix[currentPoint.X + 1, currentPoint.Y] == value)
                {
                    visitedPointsQueue.Enqueue(new Point2D(currentPoint.X + 1, currentPoint.Y));
                }
                if (currentPoint.Y > 0 && pMatrix[currentPoint.X, currentPoint.Y - 1] == value)
                {
                    visitedPointsQueue.Enqueue(new Point2D(currentPoint.X, currentPoint.Y - 1));
                }
                if (currentPoint.Y < pMatrix.GetLength(1) - 1 && pMatrix[currentPoint.X, currentPoint.Y + 1] == value)
                {
                    visitedPointsQueue.Enqueue(new Point2D(currentPoint.X, currentPoint.Y + 1));
                }
            }
            return result;
        }

        struct Point2D
        {
            private int x;
            private int y;
            public Point2D(int x = 0, int y = 0)
            {
                this.x = x;
                this.y = y;
            }
            public int X
            {
                get
                {
                    return this.x;
                }
                set
                {
                    this.x = value;
                }
            }

            public int Y
            {
                get
                {
                    return this.y;
                }
                set
                {
                    this.y = value;
                }
            }
        }
    }
}