一、题目大意标签:搜索https://leetcode.cn/problems/surrounded-regions给你一个mxn的矩阵board，由若干字符'X'和'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1：输入：board=[["X","X","X","X"],["X","O","O","X"],["X","X","O","X"],["X","O","X","X"]]输出：[["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

一、题目大意标签:搜索https://leetcode.cn/problems/word-search给定一个 mxn二维字符网格 board和一个字符串单词 word。如果 word存在于网格中，返回true；否则，返回false。单词必须按照字母顺序，通过相邻的单元格内的字母构成，其中“相邻”单元格是那些水平相邻或垂直相邻的单元格。同一个单元格内的字母不允许被重复使用。示例1：输入：board=[["A","B","C","E"],["S","F","C","S"],["A","D","E","E"]],word="ABCCED"输出：true示例2：输入：board=[["A","B",

一、题目大意标签:搜索https://leetcode.cn/problems/word-search给定一个 mxn二维字符网格 board和一个字符串单词 word。如果 word存在于网格中，返回true；否则，返回false。单词必须按照字母顺序，通过相邻的单元格内的字母构成，其中“相邻”单元格是那些水平相邻或垂直相邻的单元格。同一个单元格内的字母不允许被重复使用。示例1：输入：board=[["A","B","C","E"],["S","F","C","S"],["A","D","E","E"]],word="ABCCED"输出：true示例2：输入：board=[["A","B",