引言 Matrix内部的值修改严格来讲放在一个系列里不大合适,因为对于不同的问题,所用的算法和技巧可能完全不同,权且这样归类,以后需要时再拆分吧. 例题 1 Given a 2D board containing 'X' and 'O', capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in that surrounded region. For example,…
Given a 2D board containing 'X' and 'O', capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in that surrounded region. For example, X X X X X O O X X X O X X O X X After running your function, the board should…
在LeetCode中的Surrounded Regions 包围区域这道题中,我们发现用DFS方法中的最后一个条件必须是j > 1,如下面的红色字体所示,如果写成j > 0的话无法通过OJ,一直百思不得其解其中的原因,直到有网友告诉我说他验证了最后一个大集合在本地机子上可以通过,那么我也来验证看看吧. class Solution { public: void solve(vector<vector<char> >& board) { ; i < boar…
两种方式处理已经访问过的节点:一种是用visited存储已经访问过的1:另一种是通过改变原始数值的值,比如将1改成-1,这样小于等于0的都会停止. Number of Islands 用了第一种方式,Number of Distinct Islands用了第二种方式 200. Number of Islands 时间复杂度o(m*n) 1.这种写法要改变原始输入数组的值 错误版本: 条件判断顺序写错:grid[x][y] == '0' || x < 0 || x >= length || y…
Surrounded Regions Given a 2D board containing 'X' and 'O', capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in that surrounded region. For example, X X X X X O O X X X O X X O X X After running your function…
Leetcode之深度优先搜索(DFS)专题-130. 被围绕的区域(Surrounded Regions) 深度优先搜索的解题详细介绍,点击 给定一个二维的矩阵,包含 'X' 和 'O'(字母 O). 找到所有被 'X' 围绕的区域,并将这些区域里所有的 'O' 用 'X' 填充. 示例: X X X X X O O X X X O X X O X X 运行你的函数后,矩阵变为: X X X X X X X X X X X X X O X X 解释: 被围绕的区间不会存在于边界上,换句话说,任…
Given a 2D board containing 'X' and 'O'(the letter O), capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in that surrounded region. Example: X X X X X O O X X X O X X O X X After running your function, the boa…
Surrounded Regions Given a 2D board containing 'X' and 'O', capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in that surrounded region. For example, X X X X X O O X X X O X X O X X After running your function…
Surrounded Regions Given a 2D board containing 'X' and 'O', capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in that surrounded region. For example,X X X XX O O XX X O XX O X XAfter running your function, the…
1. Sum Root to Leaf Numbers Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number. An example is the root-to-leaf path 1->2->3 which represents the number 123. Find the total sum of all root-to-leaf num…