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hello-algo/codes/python/chapter_backtracking/preorder_traversal_ii_compa...

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"""
File: preorder_traversal_ii_compact.py
Created Time: 2023-04-15
Author: Krahets (krahets@163.com)
"""
import sys, os.path as osp
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
from modules import *
def pre_order(root: TreeNode) -> None:
"""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])