hello-algo/codes/python/chapter_backtracking/preorder_traversal_ii_compact.py
Yudong Jin a005c6ebd3
Some improvements (#1073)
* Update avatar's link in the landing page

* Bug fixes

* Move assets folder from overrides to docs

* Reduce figures' corner radius

* Update copyright

* Update header image

* Krahets -> krahets

* Update the landing page
2024-02-07 22:21:18 +08:00

42 lines
914 B
Python

"""
File: preorder_traversal_ii_compact.py
Created Time: 2023-04-15
Author: krahets (krahets@163.com)
"""
import sys
from pathlib import Path
sys.path.append(str(Path(__file__).parent.parent))
from modules import TreeNode, print_tree, list_to_tree
def pre_order(root: TreeNode):
"""前序遍历:例题二"""
if root is None:
return
# 尝试
path.append(root)
if root.val == 7:
# 记录解
res.append(list(path))
pre_order(root.left)
pre_order(root.right)
# 回退
path.pop()
"""Driver Code"""
if __name__ == "__main__":
root = list_to_tree([1, 7, 3, 4, 5, 6, 7])
print("\n初始化二叉树")
print_tree(root)
# 前序遍历
path = list[TreeNode]()
res = list[list[TreeNode]]()
pre_order(root)
print("\n输出所有根节点到节点 7 的路径")
for path in res:
print([node.val for node in path])