zoukankan      html  css  js  c++  java
  • 695. Max Area of Island

    Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water.

    Find the maximum area of an island in the given 2D array. (If there is no island, the maximum area is 0.)

    Example 1:

    [[0,0,1,0,0,0,0,1,0,0,0,0,0],
     [0,0,0,0,0,0,0,1,1,1,0,0,0],
     [0,1,1,0,1,0,0,0,0,0,0,0,0],
     [0,1,0,0,1,1,0,0,1,0,1,0,0],
     [0,1,0,0,1,1,0,0,1,1,1,0,0],
     [0,0,0,0,0,0,0,0,0,0,1,0,0],
     [0,0,0,0,0,0,0,1,1,1,0,0,0],
     [0,0,0,0,0,0,0,1,1,0,0,0,0]]
    

    Given the above grid, return 6. Note the answer is not 11, because the island must be connected 4-directionally.

    Example 2:

    [[0,0,0,0,0,0,0,0]]

    Given the above grid, return 0.

    Note: The length of each dimension in the given grid does not exceed 50.

    二维矩阵里求相连的1的最大个数

    C++(22ms):

     1 class Solution {
     2 public:
     3     int AreaOfIsland(vector<vector<int>>& grid , int i , int j){
     4         if (i >= 0 && i < grid.size() && j >= 0 && j < grid[0].size() && grid[i][j] == 1){
     5             grid[i][j] = 0 ;
     6             return 1 + AreaOfIsland(grid,i+1,j)+ AreaOfIsland(grid,i-1,j)+ AreaOfIsland(grid,i,j+1)+ AreaOfIsland(grid,i,j-1) ;
     7         }
     8         return 0 ;
     9     }
    10     
    11     int maxAreaOfIsland(vector<vector<int>>& grid) {
    12         int res = 0 ;
    13         for (int i = 0 ; i < grid.size() ; i++){
    14             for (int j = 0 ; j < grid[0].size() ; j++){
    15                 if (grid[i][j] == 1){
    16                     res = max(res,AreaOfIsland(grid,i,j)) ;
    17                 }
    18             }
    19         }
    20         return res ;
    21     }
    22 };
  • 相关阅读:
    走进AngularJs(一)angular基本概念的认识与实战
    Android开发:关于WebView
    Mysql 命令大全
    gitHub
    jquery 使用方法
    JS:offsetWidthoffsetleft 等图文解释
    offsetHeight, clientHeight与scrollHeight的区别
    Angular学习-指令入门
    jQuery学习笔记(一):入门
    JACASCRIPT--的奇技技巧的44招
  • 原文地址:https://www.cnblogs.com/mengchunchen/p/7639726.html
Copyright © 2011-2022 走看看