leetcode[113]Path Sum II

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]
]

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
void find(vector<vector<int>> &res, vector<int> tmp, TreeNode *root,int sum)
{
    if(root==NULL)return;
    if(root->left==NULL&&root->right==NULL)
    {
        if(root->val==sum)
        {
            tmp.push_back(root->val);
            res.push_back(tmp);
        }
        return;
    }
    tmp.push_back(root->val);
    find(res,tmp,root->left,sum-root->val);
    find(res,tmp,root->right,sum-root->val);
}
    vector<vector<int> > pathSum(TreeNode *root, int sum) {
        vector<vector<int>> res;
        vector<int> tmp;
        find(res,tmp,root,sum);
        return res;
    }
};