python3题解 | #求二叉树的层序遍历#
求二叉树的层序遍历
https://www.nowcoder.com/practice/04a5560e43e24e9db4595865dc9c63a3
import collections # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None # # 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可 # # # @param root TreeNode类 # @return int整型二维数组 # class Solution: def levelOrder(self , root: TreeNode) -> List[List[int]]: # write code here if not root: return [] res = [] hhh = collections.deque([root]) while hhh: ceng = [] for _ in range(len(hhh)): cur = hhh.popleft() ceng.append(cur.val) if cur.left: hhh.append(cur.left) if cur.right: hhh.append(cur.right) res.append(ceng) return res