1490

1490. Clone N-ary Tree (Medium)

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).

 

Example 1:

Input: root = [1,null,3,2,4,null,5,6]
Output: [1,null,3,2,4,null,5,6]

Example 2:

Input: root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14]
Output: [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14]

 

Constraints:

• The depth of the n-ary tree is less than or equal to 1000.
• The total number of nodes is between [0, 104].

 

Follow up: Can your solution work for the graph problem?

Companies:
Google

Related Topics:
Hash Table, Tree, Depth-First Search, Breadth-First Search

Similar Questions:

• Clone Graph (Medium)
• Copy List with Random Pointer (Medium)
• Clone Binary Tree With Random Pointer (Medium)

Solution 1.

// OJ: https://leetcode.com/problems/clone-n-ary-tree/
// Author: github.com/lzl124631x
// Time: O(N)
// Space: O(H)
class Solution {
public:
    Node* cloneTree(Node* root) {
        if (!root) return nullptr;
        auto cpy = new Node(root->val);
        for (auto &c : root->children) cpy->children.push_back(cloneTree(c));
        return cpy;
    }
};