mirror of
https://github.com/youngyangyang04/leetcode-master.git
synced 2025-07-11 04:54:51 +08:00
Update 0538.把二叉搜索树转换为累加树.md
This commit is contained in:
@ -200,8 +200,30 @@ class Solution {
|
|||||||
```
|
```
|
||||||
|
|
||||||
## Python
|
## Python
|
||||||
**递归**
|
递归法(版本一)
|
||||||
|
```python
|
||||||
|
# Definition for a binary tree node.
|
||||||
|
# class TreeNode:
|
||||||
|
# def __init__(self, val=0, left=None, right=None):
|
||||||
|
# self.val = val
|
||||||
|
# self.left = left
|
||||||
|
# self.right = right
|
||||||
|
class Solution:
|
||||||
|
def convertBST(self, root: TreeNode) -> TreeNode:
|
||||||
|
self.pre = 0 # 记录前一个节点的数值
|
||||||
|
self.traversal(root)
|
||||||
|
return root
|
||||||
|
def traversal(self, cur):
|
||||||
|
if cur is None:
|
||||||
|
return
|
||||||
|
self.traversal(cur.right)
|
||||||
|
cur.val += self.pre
|
||||||
|
self.pre = cur.val
|
||||||
|
self.traversal(cur.left)
|
||||||
|
|
||||||
|
|
||||||
|
```
|
||||||
|
递归法(版本二)
|
||||||
```python
|
```python
|
||||||
# Definition for a binary tree node.
|
# Definition for a binary tree node.
|
||||||
# class TreeNode:
|
# class TreeNode:
|
||||||
@ -234,7 +256,32 @@ class Solution:
|
|||||||
return root
|
return root
|
||||||
|
|
||||||
```
|
```
|
||||||
**迭代**
|
迭代法(版本一)
|
||||||
|
```python
|
||||||
|
class Solution:
|
||||||
|
def __init__(self):
|
||||||
|
self.pre = 0 # 记录前一个节点的数值
|
||||||
|
|
||||||
|
def traversal(self, root):
|
||||||
|
stack = []
|
||||||
|
cur = root
|
||||||
|
while cur or stack:
|
||||||
|
if cur:
|
||||||
|
stack.append(cur)
|
||||||
|
cur = cur.right # 右
|
||||||
|
else:
|
||||||
|
cur = stack.pop() # 中
|
||||||
|
cur.val += self.pre
|
||||||
|
self.pre = cur.val
|
||||||
|
cur = cur.left # 左
|
||||||
|
|
||||||
|
def convertBST(self, root):
|
||||||
|
self.pre = 0
|
||||||
|
self.traversal(root)
|
||||||
|
return root
|
||||||
|
|
||||||
|
```
|
||||||
|
迭代法(版本二)
|
||||||
```python
|
```python
|
||||||
class Solution:
|
class Solution:
|
||||||
def convertBST(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
|
def convertBST(self, root: Optional[TreeNode]) -> Optional[TreeNode]:
|
||||||
|
Reference in New Issue
Block a user