LeetCode-python 199.二叉树的右视图

题目链接
难度：中等       类型： 二叉树

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给定一棵二叉树，想象自己站在它的右侧，按照从顶部到底部的顺序，返回从右侧所能看到的节点值。

示例

输入: [1,2,3,null,5,null,4]
输出: [1, 3, 4]

解题思路

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层序遍历，输出每层的最后一个

图片来源https://leetcode-cn.com/problems/binary-tree-right-side-view/solution/er-cha-shu-de-you-shi-tu-by-leetcode/

代码实现

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def rightSideView(self, root: TreeNode) -> List[int]:
        view = []
        if root:
            level = [root]
            while level:
                view.append(level[-1].val)
                level = [kid for node in level for kid in (node.left, node.right) if kid]
        return view

本文链接：https://www.jianshu.com/p/f32b669a4dd4