leetcode994

public class Solution
    {
        int row = 0;
        int column = 0;
        int FreshOrangeCount = 0;
        int RottenOrangeCount = 0;
        int Minute = 0;
        Queue<int[]> Q = new Queue<int[]>();
        int[,] TagGrid;
        public void BFS(int[][] grid)
        {
            var rottinglist = new List<int[]>();

            while(Q.Count>0)
            {
                while (Q.Count > 0)
                {
                    var orange = Q.Dequeue();

                    int i = orange[0];
                    int j = orange[1];

                    int i_new = -1;
                    int j_new = -1;

                    //合法范围:up,down,left,right
                    //未访问的:TagGrid[newi,newj]==0
                    //新鲜的（grid[i][j]==1）
                    i_new = i - 1;
                    j_new = j;

                    //up:i-1>=0
                    if (i_new >= 0 && TagGrid[i_new, j_new] == 0 && grid[i_new][j_new] == 1)
                    {
                        FreshOrangeCount--;
                        RottenOrangeCount++;
                        TagGrid[i_new, j_new] = 1;//visited
                        grid[i_new][j_new] = 2;//go bad
                        rottinglist.Add(new int[] { i_new, j_new });
                    }

                    //down:i+1<=row-1
                    i_new = i + 1;
                    j_new = j;
                    if (i_new <= row - 1 && TagGrid[i_new, j_new] == 0 && grid[i_new][j_new] == 1)
                    {
                        FreshOrangeCount--;
                        RottenOrangeCount++;
                        TagGrid[i_new, j_new] = 1;//visited
                        grid[i_new][j_new] = 2;//go bad
                        rottinglist.Add(new int[] { i_new, j_new });
                    }

                    //left:j-1>=0
                    i_new = i;
                    j_new = j - 1;
                    if (j_new >= 0 && TagGrid[i_new, j_new] == 0 && grid[i_new][j_new] == 1)
                    {
                        FreshOrangeCount--;
                        RottenOrangeCount++;
                        TagGrid[i_new, j_new] = 1;//visited
                        grid[i_new][j_new] = 2;//go bad
                        rottinglist.Add(new int[] { i_new, j_new });
                    }

                    //right:j+1<=column-1
                    i_new = i;
                    j_new = j + 1;
                    if (j_new <= column - 1 && TagGrid[i_new, j_new] == 0 && grid[i_new][j_new] == 1)
                    {
                        FreshOrangeCount--;
                        RottenOrangeCount++;
                        TagGrid[i_new, j_new] = 1;//visited
                        grid[i_new][j_new] = 2;//go bad
                        rottinglist.Add(new int[] { i_new, j_new });
                    }

                }
                if (rottinglist.Any())
                {
                    Minute++;
                }
                foreach (var l in rottinglist)
                {
                    Q.Enqueue(l);
                }
                rottinglist.Clear();
            }
        }

        public int OrangesRotting(int[][] grid)
        {
            row = grid.Length;
            column = grid[0].Length;
            TagGrid = new int[row, column];

            for (var i = 0; i < row; i++)
            {
                for (var j = 0; j < column; j++)
                {
                    TagGrid[i, j] = 0;//unvisited
                    if (grid[i][j] == 1)
                    {
                        FreshOrangeCount++;
                    }
                    if (grid[i][j] == 2)
                    {
                        RottenOrangeCount++;
                        Q.Enqueue(new int[] { i, j });
                    }
                }
            }

            BFS(grid);

            if (FreshOrangeCount != 0)
            {
                return -1;
            }
            else
            {
                return Minute;
            }
        }
    }