/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */

class Solution {
public:
    TreeNode* sufficientSubset(TreeNode* root, int limit, int sum = 0) {
        if(root == nullptr){
            return nullptr;
        }


        // nsum = 5 + 4
        int nsum = sum + root->val;

        if(root->left == nullptr && root->right == nullptr){
            // leaf node hai ki nahi

            if(nsum < limit){
                return nullptr;
            }
            else{
                return root;
            }
        }
        else{

            root->left = sufficientSubset(root->left,limit,nsum);
            root->right = sufficientSubset(root->right,limit,nsum);

            if(root->left == nullptr && root->right == nullptr){
                return nullptr;
            }
            else{
                return root;
            }
        }
    }
};