地图中的最高点

import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.Queue;

class Solution1765 {
    public static void main(String[] args) {
        int[][] res = new Solution1765().highestPeak(new int[][]{
                {0, 1}, {0, 0}
        });
        System.out.println(Arrays.deepToString(res));
    }

    int[][] dirs = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};

    public int[][] highestPeak(int[][] isWater) {
        int m = isWater.length, n = isWater[0].length;
        int[][] ans = new int[m][n];
        for (int i = 0; i < m; ++i) {
            Arrays.fill(ans[i], -1); // -1 表示该格子尚未被访问过
        }
        Queue<int[]> queue = new ArrayDeque<int[]>();
        for (int i = 0; i < m; ++i) {
            for (int j = 0; j < n; ++j) {
                if (isWater[i][j] == 1) {
                    ans[i][j] = 0;
                    queue.offer(new int[]{i, j}); // 将所有水域入队
                }
            }
        }
        while (!queue.isEmpty()) {
            int[] p = queue.poll();
            for (int[] dir : dirs) {
                int x = p[0] + dir[0], y = p[1] + dir[1];
                if (0 <= x && x < m && 0 <= y && y < n && ans[x][y] == -1) {
                    ans[x][y] = ans[p[0]][p[1]] + 1;
                    queue.offer(new int[]{x, y});
                }
            }
        }
        return ans;
    }
}