113. Path Sum II

T

S

/**
* 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:
void resultPathSum(TreeNode* root, int sum, vector<vector<int>> &result, vector<int> &inter_result) {
if (root == nullptr) {
return;
}

inter_result.push_back(root->val);
if (root->left==nullptr && root->right==nullptr && root->val==sum) {
result.push_back(inter_result);
inter_result.pop_back();
return;
}

resultPathSum(root->left, sum-root->val, result, inter_result);
resultPathSum(root->right, sum-root->val, result, inter_result);

inter_result.pop_back();
}

vector<vector<int>> pathSum(TreeNode* root, int sum) {
vector<vector<int>> result;
vector<int> inter_result;
resultPathSum(root, sum, result, inter_result);

return result;
}
};