######python 写的广度优先的代码 class Solution: def maxDepth(self, root: TreeNode) -> int: if not root: return 0
queue=[] visited=[] queue.append(root) length=0 while queue: len1=len(queue) length+=1 for i in range(len1): node=queue.pop(0) if node.left: queue.append(node.left)
if node.right: queue.append(node.right) return length