Package g0101_0200.s0107_binary_tree_level_order_traversal_ii

Class Solution

java.lang.Object
g0101_0200.s0107_binary_tree_level_order_traversal_ii.Solution
public class Solution extends java.lang.Object
107 - Binary Tree Level Order Traversal II.

Medium

Given the root of a binary tree, return the bottom-up level order traversal of its nodes’ values. (i.e., from left to right, level by level from leaf to root).

Example 1:

Input: root = [3,9,20,null,null,15,7]

Output: [[15,7],[9,20],[3]]

Example 2:

Input: root = [1]

Output: 1

Example 3:

Input: root = []

Output: []

Constraints:

  • The number of nodes in the tree is in the range [0, 2000].
  • -1000 <= Node.val <= 1000

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    getOrder(TreeNode root, int level)
     
    java.util.List<java.util.List<java.lang.Integer>>
    levelOrderBottom(TreeNode 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

    • levelOrderBottom

      public java.util.List<java.util.List<java.lang.Integer>> levelOrderBottom(TreeNode root)

    • getOrder

      public void getOrder(TreeNode root, int level)