mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-29 09:46:29 +08:00
42 lines
1.1 KiB
Python
42 lines
1.1 KiB
Python
"""
|
|
File: binary_tree_bfs.py
|
|
Created Time: 2022-12-20
|
|
Author: a16su (lpluls001@gmail.com)
|
|
"""
|
|
|
|
import sys, os.path as osp
|
|
import typing
|
|
|
|
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
|
|
from include import *
|
|
|
|
|
|
""" 层序遍历 """
|
|
def hier_order(root: TreeNode):
|
|
# 初始化队列，加入根结点
|
|
queue = collections.deque()
|
|
queue.append(root)
|
|
# 初始化一个列表，用于保存遍历序列
|
|
res = []
|
|
while queue:
|
|
node = queue.popleft() # 队列出队
|
|
res.append(node.val) # 保存节点值
|
|
if node.left is not None:
|
|
queue.append(node.left) # 左子结点入队
|
|
if node.right is not None:
|
|
queue.append(node.right) # 右子结点入队
|
|
return res
|
|
|
|
|
|
""" Driver Code """
|
|
if __name__ == "__main__":
|
|
# 初始化二叉树
|
|
# 这里借助了一个从数组直接生成二叉树的函数
|
|
root = list_to_tree(arr=[1, 2, 3, 4, 5, 6, 7])
|
|
print("\n初始化二叉树\n")
|
|
print_tree(root)
|
|
|
|
# 层序遍历
|
|
res = hier_order(root)
|
|
print("\n层序遍历的结点打印序列 = ", res)
|
|
assert res == [1, 2, 3, 4, 5, 6, 7]
|