leetcode695.岛屿的最大面积(java)：深度优先遍历

题目

思路

具体代码

class Solution {
    public int maxAreaOfIsland(int[][] grid) {
        if(grid == null || grid.length == 0 || grid[0].length == 0){
            return 0;
        }
        int res = 0;
        for(int i = 0;i < grid.length;i++){
            for(int j = 0;j < grid[0].length;j++){
                res = Math.max(res,dfs(i,j,grid));
            }
        }
        return res;
    }
    public int dfs(int i, int j,int[][] grid){
        if(i < 0|| j < 0|| i >= grid.length || j >= grid[0].length||grid[i][j] == 0){
            return 0;
        }
        grid[i][j] = 0;
        int nums = 1;
        nums += dfs(i+1,j,grid);
        nums += dfs(i-1,j,grid);
        nums += dfs(i,j+1,grid);
        nums += dfs(i,j-1,grid);
        return nums;
    }
}