二叉树中和为某一值的路径

/*struct TreeNode {int val;struct TreeNode *left;struct TreeNode *right;TreeNode(int x) :val(x), left(NULL), right(NULL) {}};*/class Solution {public:    int num = 0;    vector<vector<int> > result;    vector<int> temp;vector<vector<int> > FindPath(TreeNode* root,int expectNumber) {if(root != NULL){            num += root->val;            temp.push_back(root->val);            //当root是根节点            if(root->left == NULL && root->right == NULL){                //当路径和值与目标值相等时                if(num == expectNumber)                    result.push_back(temp);            }else{                FindPath(root->left,expectNumber);                FindPath(root->right,expectNumber);            }            temp.pop_back();            num -= root->val;        }        return result;}};