LeetCode - Path Sum II

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    void pathSumCore(TreeNode* pNode, int sum, vector<vector<int>>& result, vector<int>& path) {
        if(pNode == NULL)
            return;


        path.push_back(pNode->val);
        if(pNode->left == NULL && pNode->right == NULL && pNode->val == sum)
            result.push_back(path);
        if(pNode->left != NULL)
            pathSumCore(pNode->left, sum - pNode->val, result, path);
        if(pNode->right != NULL)
            pathSumCore(pNode->right, sum - pNode->val, result, path);
            
        path.pop_back();
    }
    vector<vector<int>> pathSum(TreeNode *root, int sum) {
        vector<vector<int>> result;
        vector<int> path;
        pathSumCore(root, sum, result, path);
        return result;
    }
};