leetcode每日一题-岛屿的最大面积

题目分析

dfs即可，但是主要要使用沉岛思想(访问过的陆地变成水域，1变为0)

java代码

public int maxAreaOfIsland(int[][] grid) {
        if(grid==null || grid.length==0){
            return 0;
        }
        int ret = 0;
        for(int i=0;i=grid.length || j>=grid[0].length || grid[i][j]==0){
            return 0;
        }
        int num = 1;
        grid[i][j] = 0;
        num += maxAreaOfIslandCore(grid,i,j+1);
        num += maxAreaOfIslandCore(grid,i,j-1);
        num += maxAreaOfIslandCore(grid,i+1,j);
        num += maxAreaOfIslandCore(grid,i-1,j);
        return num;
    }