Leetcode 547 - Friend circles - using DFS search

Leetcode547_FriendCircles.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Leetcode547_FriendCircles
{
    /// <summary>
    /// Leetcode 547 - 
    /// https://leetcode.com/problems/friend-circles/#/description
    /// </summary>
    class Program
    {
        static void Main(string[] args)
        {
        }

        public int FindCircleNum(int[,] M)
        {
            if (M.GetLength(0) == 0 || M.GetLength(1) == 0)
            {
                return 0; 
            }

            int rows = M.GetLength(0);
            int cols = M.GetLength(1); 

            var visit = new bool[rows];            

            int count = 0;
            for (int row = 0; row < rows; row++)
            {
                if (visit[row])
                {
                    continue; 
                }

                visit[row] = true; 
                findCircleNumHelp(M, visit, row);
                count++; 
            }

            return count; 
        }

        /// <summary>
        /// depth first search - mark the row visited
        /// </summary>
        /// <param name="numbers"></param>
        /// <param name="visit"></param>
        /// <param name="row"></param>
        private static void findCircleNumHelp(int[,] numbers, bool[] visit, int row)
        {           
            int cols = numbers.GetLength(1);

            for (int col = 0; col < cols; col++)
            {
                var current = numbers[row, col];
                if (current == 0 || visit[col])
                {
                    continue; 
                }

                visit[col] = true; 
                findCircleNumHelp(numbers, visit, col); 
            }
        }
    }
}