1class Solution {2    public int orangesRotting(int[][] grid) {3        int m = grid.length, n = grid[0].length, fresh = 0, minutes = 0;4        Deque<int[]> queue = new ArrayDeque<>();5        for (int r = 0; r < m; r++) {6            for (int c = 0; c < n; c++) {7                if (grid[r][c] == 1) fresh++;8                if (grid[r][c] == 2) queue.add(new int[]{r, c});9            }10        }11        int[][] directions = {{1,0},{-1,0},{0,1},{0,-1}};12        while (fresh > 0 && !queue.isEmpty()) {13            int size = queue.size();14            for (int i = 0; i < size; i++) {15                int[] cell = queue.remove();16                for (int[] d : directions) {17                    int r = cell[0] + d[0], c = cell[1] + d[1];18                    if (r < 0 || c < 0 || r >= m || c >= n || grid[r][c] != 1) continue;19                    grid[r][c] = 2; fresh--;20                    queue.add(new int[]{r, c});21                }22            }23            minutes++;24        }25        return fresh == 0 ? minutes : -1;26    }27}