hello-algo/codes/python/chapter_backtracking/preorder_traversal_i_compact.py
2023-04-23 19:36:07 +08:00

35 lines
752 B
Python

"""
File: preorder_traversal_i_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:例题一"""
if root is None:
return
if root.val == 7:
# 记录解
res.append(root)
pre_order(root.left)
pre_order(root.right)
"""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
res = list[TreeNode]()
pre_order(root)
print("\n输出所有值为 7 的节点")
print([node.val for node in res])