1490.Clone N-ary Tree

Tags: Medium Tree

Links: https://leetcode-cn.com/problems/clone-n-ary-tree/

---

Given a rootof 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).

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

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, 10^4].

---

/*
// 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) {
        std::ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        cout.tie(NULL);

        if (!root) return root;

        Node *res = new Node(root -> val);
        int n = root -> children.size();
        res -> children.resize(n);
        for (int i = 0; i < n; ++i) {
            res -> children[i] = cloneTree(root -> children[i]);
        }

        return res;
    }
};