K Index - using Queue, search array uses two dimensional array.

KIndexUsingQueueP3.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)
        {            
            return searchUsingQueue(arr, row, col, row, col, kIndex, search, MaxRow);
        }

        /*
         * April 20, 2016
         * searchA using two dimensional array, and default value 0 - stands for unvisited. 
         * 
         * April 19, 2016
         * Two dimension array arr[,], use getLength(0) and getLength(1) for first and second dimension length;
         * But, jagged array - arr[][], getLength(1) will throw exception - 
         */
        private static bool searchUsingQueue(int[][] arr, int oriX, int oriY, int x, int y, int kIndex, int search, int MaxRow)
        {
            int rows = arr.Length;   // or arr.getLength()
            int cols = arr[0].Length;

            int[,] searchedA = new int[rows, cols]; // 0 - unvisited 

            if (!isValid(x, MaxRow) || !isValid(y, MaxRow) || kIndex < 0)
                return false;

            Queue<string> queue = new Queue<string>();

            searchedA[x, y] = 1;  // mark as visited 
            queue.Enqueue(getKey(x, y, kIndex));

            while (queue.Count > 0)
            {
                string key = (string)queue.Dequeue();

                string[] kA = key.Split(';');

                int tmpX = Convert.ToInt32(kA[0]);
                int tmpY = Convert.ToInt32(kA[1]);
                int indexCount = Convert.ToInt32(kA[2]);

                if (notSame(tmpX, tmpY, oriX, oriY) && arr[tmpX][tmpY] == arr[oriX][oriY])
                    return true;
                
                if (indexCount > 0)
                {
                    int newCount = indexCount - 1; 
                    int[][] neighbors = new int[4][]{
                        new int[2]{-1, 0},
                        new int[2]{0, -1}, 
                        new int[2]{1, 0}, 
                        new int[2]{0, 1}
                    }; 

                    for(int i= 0; i< neighbors.GetLength(0); i++)
                    {
                        int nX = tmpX + neighbors[i][0]; 
                        int nY = tmpY + neighbors[i][1]; 
                        
                        if (isInRange(nX, nY, rows, cols) && searchedA[nX, nY] == 0)
                        {
                            searchedA[nX, nY] = 1; 
                            queue.Enqueue(getKey(nX, nY, newCount)); 
                        }
                    }
                }
            }

            return false; 
        }

        private static bool isInRange(int x, int y, int row, int col)
        {
            if (x >= 0 && x < row && y >= 0 && y < col)
                return true;
            return false; 

        }
        private static string getKey(int row, int col, int kIndex)
        {
            return row.ToString() + ";" + col.ToString() + ";" + kIndex.ToString(); 
        }

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

        private static bool notSame(int x1, int y1, int x2, int y2)
        {
            return Math.Abs(x1 - x2) + Math.Abs(y1 - y2) > 0; 
        }

    }
}