maze - using queue - four directions

maze_usingQueue_FourDirections.cs

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

namespace MazeProject
{
    /// <summary>
    /// code review - July 18, 2017
    /// Maze - 
    /// Given an array, there is only one item is value of 9, all others are 0 or 1. 
    /// 0 stands for the exit is not availabe, 1 is ok to continue. Make a judgement 
    /// if starting from (0,0), 4 directions: upper, down, left and right, and see 
    /// if there is path to find 9.
    /// </summary>
    class Program
    {
        static void Main(string[] args)
        {
            var maze = new int[3][]{
                new int[]{1, 0, 0, 1}, 
                new int[]{1, 1, 1, 1}, 
                new int[]{1, 0, 0, 9}};

            printMatrix(maze);
            Console.WriteLine(checkMaze(maze));
        }        

        public static int checkMaze(int[][] maze)
        {
            if (maze == null || maze.Length == 0 || maze[0][0] == 0)
            {
                return 0;
            }

            if (maze[0][0] == 9)
            {
                return 1;
            }

            int rows = maze.Length;
            int columns = maze[0].Length;

            var queue = new Queue<int[]>();

            queue.Enqueue(new int[] { 0, 0 });

            maze[0][0] = 0;

            while (queue.Count > 0)
            {
                var visit = queue.Dequeue();
                var row = visit[0];
                var col = visit[1];                 
                                
                if( visitNeighbor(row + 1, col, ref queue, maze ) ||
                    visitNeighbor(row - 1, col, ref queue, maze ) ||
                    visitNeighbor(row, col + 1, ref queue, maze ) ||
                    visitNeighbor(row, col - 1, ref queue, maze ))                
                {
                    return 1; 
                }
            }

            return 0;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="row"></param>
        /// <param name="column"></param>
        /// <param name="queue"></param>
        /// <param name="maze"></param>
        /// <returns></returns>
        private static bool visitNeighbor(int row, int column, ref Queue<int[]> queue, int[][] maze)
        {
            int rows = maze.Length;
            int columns = maze[0].Length;

            if (row < 0 || row >= rows || column < 0 || column >= columns)
            {
                return false; 
            }

            var visit = maze[row][column];

            if (visit == 9)
            {
                return true; 
            }

            if (visit == 1)
            {
                maze[row][column] = 0; // mark as visited
                queue.Enqueue(new int[]{row, column}); 
            }

            return false; 
        }

        public static void printMatrix(int[][] matrix)
        {
            int m = matrix.Length;
            int n = matrix[0].Length;

            for (int i = 0; i < m; i++)
            {
                for (int j = 0; j < n; j++)
                {
                    Console.WriteLine(matrix[i][j] + " ");
                }

                Console.WriteLine("");
            }
        }
    }
}