新节点引导的问题

解决"新节点引导的问题"可以使用以下代码示例：

1. 使用递归搜索算法

class TreeNode:
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right

def search_node(root, target):
    if root is None:
        return None
    if root.val == target:
        return root
    left_result = search_node(root.left, target)
    if left_result:
        return left_result
    right_result = search_node(root.right, target)
    if right_result:
        return right_result
    return None

# 创建测试树
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)
root.left.right = TreeNode(5)

target_node = search_node(root, 4)
if target_node:
    print("找到了目标节点: ", target_node.val)
else:
    print("未找到目标节点")

2. 使用层序遍历算法

from collections import deque

class TreeNode:
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right

def search_node(root, target):
    if root is None:
        return None
    
    queue = deque([root])
    while queue:
        node = queue.popleft()
        if node.val == target:
            return node
        if node.left:
            queue.append(node.left)
        if node.right:
            queue.append(node.right)
    return None

# 创建测试树
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)
root.left.right = TreeNode(5)

target_node = search_node(root, 4)
if target_node:
    print("找到了目标节点: ", target_node.val)
else:
    print("未找到目标节点")

这两种方法都可以用来解决"新节点引导的问题"，其中递归搜索算法适用于树结构较小且不会过深的情况，而层序遍历算法适用于任意大小的树结构。