# Leetcode: https://leetcode.com/problems/binary-tree-right-side-view/description/

# I've done so many of these level by level traversals that it's pretty straight forward now.

# Beats 90%, seems strange for deleting entire objects.

# Definition for a binary tree node.

# class TreeNode(object):

# def __init__(self, x):

# self.val = x

# self.left = None

# self.right = None

class Solution(object):

def rightSideView(self, root):

"""

:type root: TreeNode

:rtype: List[int]

"""

# Always return the right most element per level.

# Level by level traversal

if not root:

return []

queue = [(root)]

ret = []

while (len(queue) > 0):

copy = queue[:]

del queue[:]

for i in xrange(len(copy)):

if (copy[i].left):

queue.append(copy[i].left)

if (copy[i].right):

queue.append(copy[i].right)

ret.append(copy[-1].val)

return ret