Path Sum II

Description:

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 and sum = 22,

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

return

[
   [5,4,11,2],
   [5,8,4,5]
]

Code:

 1 void pathSum(TreeNode* root, int sum, vector<int>&path,vector< vector<int> >&result)
 2     {
 3         path.push_back(root->val);
 4           if (root->left == NULL && root->right == NULL && root->val == sum)
 5                     result.push_back(path);
 6             if (root->left!=NULL)
 7                 pathSum(root->left, sum-root->val, path,result);
 8             if (root->right!=NULL)
 9                 pathSum(root->right, sum-root->val, path,result);
10             path.pop_back();   
11     }
12     vector<vector<int>> pathSum(TreeNode* root, int sum) {
13         vector< vector<int> >result;
14         if (root==NULL)
15            return result;   
16         vector<int>path;
17         pathSum(root,sum,path,result);
18         return result;
19     }

 

posted @ 2015-07-04 17:35  Rosanne  阅读(178)  评论(0)  编辑  收藏  举报