K index - algorithm practice

kIndex.cs

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

namespace kIndex
{
    class Program
    {
        static void Main(string[] args)
        {
            int k = Convert.ToInt16(Console.ReadLine());

            int[][] arr = new int[k][];

            for (int i = 0; i < k; i++)
                arr[i] = new int[k];

            for (int i = 0; i < k; i++)
            {
                string s = Console.ReadLine();
                string[] aA = s.Split(' ');
                if (aA.Length != k)
                    return;
                for (int j = 0; j < k; j++)
                    arr[i][j] = Convert.ToInt16(aA[j].Trim());
            }

            int kIndex = Convert.ToInt16(Console.ReadLine());
            if (kIndexFunc(arr, kIndex))
            {
                Console.WriteLine("YES");
            }
            else
                Console.WriteLine("NO");
        }

        public static bool kIndexFunc(int[][] arr, int kIndex)
        {
            if (arr == null) return false;

            int m = arr.Length;
            int n = arr[0].Length;
            if (m != n)
                return false;

            for (int i = 0; i < m; i++)
                for (int j = 0; j < m; j++)
                {
                    int search = arr[i][j];
                    if (searchInKIndex(arr, i, j, kIndex, search, m))
                        return true;
                }
            return false; 
        }

        private static bool searchInKIndex(int[][] arr, int row, int col, int kIndex, int search, int MaxRow)
        {
            bool[][] searchedA = new bool[MaxRow][];

            for (int i = 0; i < MaxRow; i++)
                searchedA[i] = new bool[MaxRow];

            for (int i = 0; i < MaxRow; i++)
                for (int j = 0; j < MaxRow; j++)
                    searchedA[i][j] = false; 

                    // up, down, left, right
            return DFS(arr, row, col, row, col, kIndex , search, MaxRow, searchedA);                

        }

        private static bool DFS(int[][] arr, int oriX, int oriY, int row, int col, int kIndex, int search, int MaxRow, bool[][] searchedA)
        {
            if (!isValid(row, MaxRow) || !isValid(col, MaxRow) || kIndex < 0)
                return false;

            if(Math.Abs(oriX -row) +Math.Abs(oriY-col) >0 && !searchedA[row][col])
            {
                if (arr[oriX][oriY] == arr[row][col]) 
                    return true; 
            }
            else
            {
                searchedA[row][col] = true;

                DFS(arr, oriX, oriY, row-1, col, kIndex-1, search, MaxRow, searchedA);
                DFS(arr, oriX, oriY, row+1,  col,  kIndex-1, search, MaxRow, searchedA);
                DFS(arr, oriX, oriY, row, col+1, kIndex-1, search, MaxRow, searchedA);
                DFS(arr, oriX, oriY, row, col-1, kIndex-1, search, MaxRow, searchedA); 

            }

            return false; 
        }

        private static bool isValid(int row, int MaxRow)
        {
            if (row >= 0 && row < MaxRow)
                return true;
            else
                return false; 
        }

    }
}