1490. Clone N-ary Tree

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<Node> children;
}

Nary-Tree input serialization is represented in their level order traversal, each group of children is separated by the null value (See examples).

/*
// 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 {
    Node* _clone(Node* root) {
        Node* node = new Node(root->val);
        for(auto ch : root->children) {
            node->children.push_back(cloneTree(ch));
        }
        return node;
    }
public:
    Node* cloneTree(Node* root) {
        if(!root) return nullptr;
        return _clone(root);
    }
};