LC 0107 [E] Binary Tree Level Order Traversal II - ALawliet/algorithms GitHub Wiki
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, val=0, left=None, right=None):
# self.val = val
# self.left = left
# self.right = right
class Solution:
def levelOrderBottom(self, root: TreeNode) -> List[List[int]]:
res = deque()
if root is None: return res
Q = deque([root])
while Q:
levelSize = len(Q)
currentLevel = []
for _ in range(levelSize):
currentNode = Q.popleft()
currentLevel.append(currentNode.val)
if currentNode.left:
Q.append(currentNode.left)
if currentNode.right:
Q.append(currentNode.right)
res.appendleft(currentLevel)
return res