Clone n ary tree

Hash Table Tree Depth-First Search Breadth-First Search

83.1% acceptance

Mar 31, 2026

427

Given a root of an N-ary tree, return a deep copy (clone) of the tree. Each node in the n-ary tree contains a val (int) and a list (List[Node]) of its children. class Node { public int val; public List children; } Nary-Tree input serialization is represented in their level order traversal, each group of children is separated by the null value (See examples).

Solution

C++

Time O(n)

Space O(1)

LeetCode

solution.cpp

/*
// Definition for a Node.
class Node {
public:
  int val;
  vector<Node*> children;

  Node() {}

  Node(int _val) {
    val = _val;
  }

  Node(int _val, vector<Node*> _children) {
    val = _val;
    children = _children;
  }
};
*/

class Solution {
public:
  Node* cloneTree(Node* root) {
    if (!root) return nullptr;
    Node* clone = new Node(root->val);
    for (auto* child : root->children) {
      clone->children.push_back(cloneTree(child));
    }
    return clone;
  }
};