From e7b7aa8e4a85d49933ddfa14e4911cc8d0f72bfe Mon Sep 17 00:00:00 2001 From: jianghongcheng <35664721+jianghongcheng@users.noreply.github.com> Date: Tue, 23 May 2023 21:16:37 -0500 Subject: [PATCH] =?UTF-8?q?Update=200235.=E4=BA=8C=E5=8F=89=E6=90=9C?= =?UTF-8?q?=E7=B4=A2=E6=A0=91=E7=9A=84=E6=9C=80=E8=BF=91=E5=85=AC=E5=85=B1?= =?UTF-8?q?=E7=A5=96=E5=85=88.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...35.二叉搜索树的最近公共祖先.md | 49 ++++++++++++++----- 1 file changed, 36 insertions(+), 13 deletions(-) diff --git a/problems/0235.二叉搜索树的最近公共祖先.md b/problems/0235.二叉搜索树的最近公共祖先.md index 8353303a..9777bb0b 100644 --- a/problems/0235.二叉搜索树的最近公共祖先.md +++ b/problems/0235.二叉搜索树的最近公共祖先.md @@ -275,34 +275,57 @@ class Solution { ## Python -递归法: +递归法(版本一) ```python class Solution: - """二叉搜索树的最近公共祖先 递归法""" + def traversal(self, cur, p, q): + if cur is None: + return cur + # 中 + if cur.val > p.val and cur.val > q.val: # 左 + left = self.traversal(cur.left, p, q) + if left is not None: + return left - def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode': - if root.val > p.val and root.val > q.val: - return self.lowestCommonAncestor(root.left, p, q) - if root.val < p.val and root.val < q.val: - return self.lowestCommonAncestor(root.right, p, q) - return root + if cur.val < p.val and cur.val < q.val: # 右 + right = self.traversal(cur.right, p, q) + if right is not None: + return right + + return cur + + def lowestCommonAncestor(self, root, p, q): + return self.traversal(root, p, q) ``` -迭代法: +迭代法(版本二)精简 ```python class Solution: - """二叉搜索树的最近公共祖先 迭代法""" + def lowestCommonAncestor(self, root, p, q): + if root.val > p.val and root.val > q.val: + return self.lowestCommonAncestor(root.left, p, q) + elif root.val < p.val and root.val < q.val: + return self.lowestCommonAncestor(root.right, p, q) + else: + return root - def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode': - while True: +``` + +迭代法 +```python +class Solution: + def lowestCommonAncestor(self, root, p, q): + while root: if root.val > p.val and root.val > q.val: root = root.left elif root.val < p.val and root.val < q.val: root = root.right else: return root -``` + return None + +``` ## Go 递归法: