""" 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])