题目

image.png

思路

  • 深度优先+剪枝

    代码

    1.   public int maxAreaOfIsland(int[][] grid) {
    2.       int res = 0;
    3.       for (int i = 0; i < grid.length; i++) {
    4.           for (int j = 0; j < grid[0].length; j++) {
    5.               if (grid[i][j] == 1)
    6.                   res = Math.max(res, dfs(grid, i, j));
    7.           }
    8.       }
    9.       return res;
    10.   }
    12.   public int dfs(int[][] grid, int i, int j) {
    13.       if (i < 0 || j < 0 || i >= grid.length || j >= grid[0].length || grid[i][j] == 0) 
    14.           return 0;
    15.       grid[i][j] = 0;
    16.       int res =  dfs(grid, i - 1, j) + dfs(grid, i, j - 1) 
    17.                       + dfs(grid, i + 1, j) + dfs(grid, i, j + 1) + 1;
    18.       return res;
    19.   }

    岛屿的最大面积