Algorithms - 06. Connected Areas in Matrix

using System;
using System.Collections.Generic;
using System.Linq;

namespace Algorithms
{
    class Program
    {
        static char wall = '*';
        static char visited = 'v';
        static List<Area> areas = new List<Area>();
        static void Main(string[] args)
        {
            int rows = int.Parse(Console.ReadLine());
            int cols = int.Parse(Console.ReadLine());
            char[,] matrix = ReadMatrix(rows, cols);

            for (int row = 0; row < matrix.GetLength(0); row++)
            {
                for (int col = 0; col < matrix.GetLength(1); col++)
                {
                    FindConnectedArea(matrix, row, col);
                }
            }


            Console.WriteLine($"Total areas found: {areas.Count}");

            int positionCount = 1;

            foreach (var area in areas.OrderByDescending(a => a.size))
            {
                Console.WriteLine($"Area #{positionCount++} at ({area.row}, {area.col}), size: {area.size}");
            }

        }

        private static void FindConnectedArea(char[,] matrix, int row, int col)
        {
            if (matrix[row, col] == wall || matrix[row, col] == visited)
            {
                return;
            }

            Area area = new Area(row, col);
            FillArea(matrix, row, col, area);

            areas.Add(area);
        }

        private static void FillArea(char[,] matrix, int row, int col, Area area)
        {
            if (!IsInRange(matrix, row, col)
                || matrix[row, col] == visited
                || matrix[row, col] == wall)
            {
                return;
            }

            matrix[row, col] = visited;
            area.size++;

            FillArea(matrix, row + 1, col, area);
            FillArea(matrix, row, col + 1, area);
            FillArea(matrix, row - 1, col, area);
            FillArea(matrix, row, col - 1, area);

        }

        private static bool IsInRange(char[,] matrix, int row, int col)
        {
            return row >= 0 && row < matrix.GetLength(0) && col >= 0 && col < matrix.GetLength(1);
        }

        private static char[,] ReadMatrix(int rows, int cols)
        {
            var matrix = new char[rows, cols];

            for (int i = 0; i < rows; i++)
            {
                var currentRow = Console.ReadLine().ToCharArray();

                for (int j = 0; j < currentRow.Length; j++)
                {
                    matrix[i, j] = currentRow[j];
                }
            }
            return matrix;
        }

        class Area : IComparable<Area>
        {
            public int row;
            public int col;

            public int size;

            public Area(int row, int col)
            {
                this.row = row;
                this.col = col;

                this.size = 0;
            }

            public int CompareTo(Area other)
            {
                int comperator = other.size.CompareTo(this.size);

                if (comperator == 0)
                {
                    comperator = this.row.CompareTo(other.row);
                }

                if (comperator == 0)
                {
                    comperator = this.col.CompareTo(other.col);
                }

                return comperator;
            }
        }
    }
}