完全二叉树特点:层序遍历遇到第一个None后,后面一定全是None
import queue class Solution: def isCompleteTree(self , root: TreeNode) -> bool: q = queue.Queue() q.put(root) flag = 0 while not q.empty(): node = q.get() if not node: # 完全二叉树特点:层序遍历遇到第一个None后,后面一定全是None flag = 1 else: if flag:return False q.put(node.left) q.put(node.right) return True