LeetCode题解之Binary Tree Paths

1、题目描述

2、分析

使用递归。

3、代码

 1 vector<string> ans;
 2     
 3     vector<string> binaryTreePaths(TreeNode* root) {
 4          
 5         if (root == NULL) return ans;
 6         leafPath(root,"");
 7         return ans;
 8         
 9         
10     }
11     
12     void leafPath(TreeNode *root, string s)
13     {
14         if (root == NULL)
15             return ;
16         if (root->left == NULL && root->right == NULL){
17             string stmp = s + to_string(root->val);
18             ans.push_back(stmp);
19             return ;
20         } else {
21             string stmp = s  + to_string(root->val) + "->";
22             leafPath(root->left, stmp);
23             leafPath(root->right, stmp);
24         }
25         
26     }