剑指office--------二叉树中和为某一值的路径

 1 /*
 2 struct TreeNode {
 3     int val;
 4     struct TreeNode *left;
 5     struct TreeNode *right;
 6     TreeNode(int x) :
 7             val(x), left(NULL), right(NULL) {
 8     }
 9 };*/
10 class Solution {
11 public:
12     void Cal(TreeNode* root,vector<int> way,vector<vector<int> > &ans,int expectNumber,int sum){
13         way.push_back(root->val);
14         if (root->left==NULL&&root->right==NULL){
15             if (sum==expectNumber){
16 //                way.push_back(root->val);
17                 ans.push_back(way);
18                 return ;
19             }
20             return ;
21         }
22 //        if (sum>expectNumber)    return ;
23         if (root->left!=NULL){
24            
25             Cal(root->left,way,ans,expectNumber,sum+root->left->val);
26         }
27         if (root->right!=NULL){
28             
29             Cal(root->right,way,ans,expectNumber,sum+root->right->val);
30         }
31         return ;
32     }
33     vector<vector<int> > FindPath(TreeNode* root,int expectNumber) {
34         
35         vector<vector<int> > ans;
36         if (root==NULL)    return ans;
37         vector<int> way;
38         
39         Cal(root,way,ans,expectNumber,root->val);
40         return ans;
41     }
42 };