← 返回 google 的题目列表Binary Tree Right Side View
类型：online_judge
Given a binary tree, return the values of the nodes you can see when looking from the right side.
Example
Input: Binary tree [1, 2, 3, null, 5, null, 4]
1
/ \
2 3
\ \
5 4
Output: [1, 3, 4]
Requirements
Use breadth-first search (BFS) algorithm. For each level, output the last node in that level.
Constraints
The number of nodes in the tree is in the range [0, 100].
-100 <= Node value <= 100
Example
Input
[1, 2, 3, null, 5, null, 4]