题目链接：79. 单词搜索 - 力扣（LeetCode）

要在一个二维数组里面找到一条单词路径，可以先遍历二维数组找到单词入口，然后往上下左右深度遍历，访问过的元素直接修改成字符串结束符，访问完改回去

class Solution {
public:string word;int row, column;vector<vector<char> > board;bool dfs(int i, int j, int count) {if (i >= row || j >= column || i < 0 || j < 0 || board[i][j] != word[count])return false;if (count == word.size() - 1)return true;board[i][j] = '\0';++count;bool next = dfs(i - 1, j, count) || dfs(i, j - 1, count) || dfs(i + 1, j, count) || dfs(i, j + 1, count);board[i][j] = word[--count];return next;}bool exist(vector<vector<char> > &board, string word) {this->board = move(board);this->word = move(word);row = this->board.size();column = this->board[0].size();for (int i = 0; i < row; ++i)for (int j = 0; j < column; ++j) {if (dfs(i, j, 0))return true;}return false;}
};