LeetCode 257. Binary Tree Paths

题目链接：https://leetcode.com/PRoblems/binary-tree-paths/?tab=Description

题目描述：

Given a binary tree, return all root-to-leaf paths.

For example, given the following binary tree:

   1 /   /2     3 /  5
All root-to-leaf paths are:
["1->2->5", "1->3"]思路：题目很简单，直接用DFS遍历保存路径即可
代码：
/** * 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> binaryTreePaths(TreeNode* root) {        vector<string> result;        string tmpPath="";        DFS(root,tmpPath,result);        return result;    }    void DFS(TreeNode* root,string path,vector<string> &Paths)    {        if(root==NULL)             return;        if(root->left==NULL&&root->right==NULL)        {            path+=to_string(root->val);            Paths.push_back(path);            return;        }        path+=to_string(root->val);        path+="->";        DFS(root->left,path,Paths);        DFS(root->right,path,Paths);    }};