Path Sum II C++ 实现 解题 LEETCODE

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:    vector<vector<int>> ret;    void path(TreeNode *root,int sum,int cursum,vector<int>vec)    {        if(root==NULL)        return ;        if(root->left==NULL&&root->right==NULL)        {            if(cursum+root->val==sum)            {                vec.push_back(root->val);                ret.push_back(vec);            }            return ;        }        vec.push_back(root->val);        path(root->left,sum,cursum+root->val,vec);       path(root->right,sum,cursum+root->val,vec);            }    vector<vector<int> > pathSum(TreeNode *root, int sum) {        ret.clear();        vector<int>rec;        path(root,sum,0,rec);        return ret;    }};