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]]

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代码如下：

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