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 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 and Description
Solution()

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Detail

Solution

public Solution()

Method Detail

levelOrderBottom

public List<List<Integer>> levelOrderBottom(TreeNode root)

getOrder

public void getOrder(TreeNode root,
                     int level)