Package g0501_0600.s0589_n_ary_tree_preorder_traversal

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    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 <code>0, 10<sup>4</sup></code>.

    • <code>0 <= Node.val <= 10<sup>4</sup></code>

    • 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?

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final List<Integer> preorder(Node root)

      • Methods inherited from class java.lang.Object

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