Leetcode 113. 路径总和 II

/**
* 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>> res;
vector<int> aux;

void pathSum1(TreeNode* root, int sum)
{
if(root->left == root->right)
{
if(sum == root->val)
{
aux.push_back(sum);
res.push_back(aux);
aux.pop_back();
}
}

aux.push_back(root->val);
if(root->left)
{
pathSum1(root->left, sum-root->val);
}

if(root->right)
{
pathSum1(root->right, sum-root->val);
}
aux.pop_back();
}

vector<vector<int>> pathSum(TreeNode* root, int sum) {
res.clear();
if(root==NULL)
return vector<vector<int>>();
pathSum1(root, sum);
return res;
}
};