LeetCode题解之Binary Tree Paths

1、题目描述

2、分析

使用递归。

3、代码

 vector<string> ans;

     vector<string> binaryTreePaths(TreeNode* root) {

         if (root == NULL) return ans;
         leafPath(root,"");
         return ans;

     }

     void leafPath(TreeNode *root, string s)
     {
         if (root == NULL)
             return ;
         if (root->left == NULL && root->right == NULL){
             string stmp = s + to_string(root->val);
             ans.push_back(stmp);
             return ;
         } else {
             string stmp = s  + to_string(root->val) + "->";
             leafPath(root->left, stmp);
             leafPath(root->right, stmp);
         }

     }