diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index 07708e5a..a02cf997 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -279,29 +279,29 @@ python代码: ```python class Solution: + """二叉树层序遍历II迭代解法""" + def levelOrderBottom(self, root: TreeNode) -> List[List[int]]: + results = [] if not root: - return [] - quene = [root] - out_list = [] + return results - while quene: - in_list = [] - for _ in range(len(quene)): - node = quene.pop(0) - in_list.append(node.val) - if node.left: - quene.append(node.left) - if node.right: - quene.append(node.right) - - out_list.append(in_list) - - out_list.reverse() - return out_list - -# 执行用时:36 ms, 在所有 Python3 提交中击败了92.00%的用户 -# 内存消耗:15.2 MB, 在所有 Python3 提交中击败了63.76%的用户 + from collections import deque + que = deque([root]) + + while que: + result = [] + for _ in range(len(que)): + cur = que.popleft() + result.append(cur.val) + if cur.left: + que.append(cur.left) + if cur.right: + que.append(cur.right) + results.append(result) + + results.reverse() + return results ``` Java: