[leetcode]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 {    vector<vector<int>> result;public:    void path(TreeNode *root, int sum, vector<int> tmp){        if(!root ->left && !root->right){            if(root -> val == sum){                tmp.push_back(root -> val);                result.push_back(tmp);            }        }                int next_sum = sum - root -> val;        tmp.push_back(root -> val);                if(root -> left){            path(root -> left, next_sum, tmp);        }        if(root -> right){            path(root -> right, next_sum, tmp);        }                    }    vector<vector<int> > pathSum(TreeNode *root, int sum) {        // Start typing your C/C++ solution below        // DO NOT write int main() function        result.clear();        if(!root) return result;        vector<int> tmp;        path(root, sum, tmp);                return result;    }};