Update preorder_traversal_iii.

codes/python/chapter_backtracking/preorder_traversal_iii_compact.py

@@ -39,6 +39,6 @@ if __name__ == "__main__":
     res = list[list[TreeNode]]()
     pre_order(root)
 
-    print("\n输出所有根节点到节点 7 的路径，路径中不包含值为 3 的节点，仅包含一个值为 7 的节点")
+    print("\n输出所有根节点到节点 7 的路径，路径中不包含值为 3 的节点")
     for path in res:
         print([node.val for node in path])

codes/python/chapter_backtracking/preorder_traversal_iii_template.py

@@ -43,7 +43,6 @@ def backtrack(
     if is_solution(state):
         # 记录解
         record_solution(state, res)
-        return
     # 遍历所有选择
     for choice in choices:
         # 剪枝：检查选择是否合法

codes/python/modules/__init__.py

@@ -9,7 +9,7 @@ from .list_node import (
     linked_list_to_list,
     get_list_node,
 )
-from .tree_node import TreeNode, list_to_tree, tree_to_list, get_tree_node
+from .tree_node import TreeNode, list_to_tree, tree_to_list
 from .vertex import Vertex, vals_to_vets, vets_to_vals
 from .print_util import (
     print_matrix,

codes/python/modules/tree_node.py

@@ -67,14 +67,3 @@ def tree_to_list(root: TreeNode | None) -> list[int]:
     res = []
     tree_to_list_dfs(root, 0, res)
     return res
-
-
-def get_tree_node(root: TreeNode | None, val: int) -> TreeNode | None:
-    """Get a tree node with specific value in a binary tree"""
-    if not root:
-        return
-    if root.val == val:
-        return root
-    left: TreeNode | None = get_tree_node(root.left, val)
-    right: TreeNode | None = get_tree_node(root.right, val)
-    return left if left else right