Path Sum II @LeetCode

PROBLEM :

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]
]

--------------------------------------------------------------------------------
SIMPLE c++ IMPLEMENTATION : (Recursive Solution)
--------------------------------------------------------------------------------

/**
 * 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>> pathSum(TreeNode* root, int sum) {
        vector<vector<int>> vec ;
        vector<int> row ;
        PathSumCheck(root,sum,vec,row) ;
        return vec ;
    }
   
    void PathSumCheck(TreeNode* root,int sum,vector<vector<int>> &vec,vector<int> row){
        if(root==NULL)
            return ;
           
        row.push_back(root->val) ;
        sum-=root->val ;
       
        if(sum==0&&(root->left==NULL&&root->right==NULL))
            vec.push_back(row) ;
           
        PathSumCheck(root->left,sum,vec,row) ;
        PathSumCheck(root->right,sum,vec,row) ;
    }
};

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