EEPW论坛

Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.

For example:
Given the below binary tree andsum = 22,

              5
             / \
            4   8
           /   / \
          11  13  4
         /  \    / \
        7    2  5   1

return

[
   [5,4,11,2],
   [5,8,4,5]
]

1. class Solution {  

2. public:  

3.     vector<vector<int>> pathSum(TreeNode* root, int sum)  

4.     {  

5.         vector<vector<int>> ret;  

6.         vector<int> tmp;  

7.         pathSumone(root, sum, ret, tmp);  

8.     }  

9.     void pathSumone(TreeNode* root, int sum, vector<vector<int>>& vv, vector<int> tmp)  

10.     {  

11.         if (root==NULL)  

12.         {  

13.             return;  

14.         }  

15.   

16.         tmp.push_back(root->val);  

17.         if (root->left==NULL && root->right==NULL && sum-root->val==0)  

18.         {  

19.             vv.push_back(tmp);  

20.         }  

21.         pathSumone(root->left, sum-root->val, vv, tmp);  

22.         pathSumone(root->right, sum-root->val, vv, tmp);  

23.     }  

24. };  

题意：返回所有路径和为sum的所有路径；