199. Binary Tree Right Side View

199. Binary Tree Right Side View
class Solution(object):
def rightSideView(self, root):
"""
:type root: TreeNode
:rtype: List[int]
"""
if root == None:
return []
qu = [root]
res = []
while qu:
temp = len(qu)
for i in range(temp):
node = qu.pop(0)
if node.left:
qu.append(node.left)
if node.right:
qu.append(node.right)
if i == temp - 1:
res.append(node.val)
return res