leetcode257. 二叉树的所有路径

1、题目

https://leetcode-cn.com/problems/binary-tree-paths/

2、题意

题解1：dfs

/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: vector<string> res; void dfs(string path,TreeNode*&root) { if(root) { path+=to_string(root->val); if(!root->left&&!root->right) res.push_back(path); else path+="->"; dfs(path,root->left); dfs(path,root->right); } } vector<string> binaryTreePaths(TreeNode* root) { dfs("",root); return res; } };