Package g0501_0600.s0589_n_ary_tree_preorder_traversal

Class Solution

java.lang.Object
g0501_0600.s0589_n_ary_tree_preorder_traversal.Solution
public class Solution extends java.lang.Object
589 - N-ary Tree Preorder Traversal.

Easy

Given the root of an n-ary tree, return the preorder traversal of its nodes’ values.

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: [1,3,5,6,2,4]

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: [1,2,3,6,7,11,14,4,8,12,5,9,13,10]

Constraints:

  • The number of nodes in the tree is in the range [0, 104].
  • 0 <= Node.val <= 104
  • The height of the n-ary tree is less than or equal to 1000.

Follow up: Recursive solution is trivial, could you do it iteratively?

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    java.util.List<java.lang.Integer>
    preorder(Node root)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • preorder

      public java.util.List<java.lang.Integer> preorder(Node root)