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🐱(tree): 235. 二叉搜索树的最近公共祖先
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‎docs/data-structure/tree/recursion/README.md‎

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return root
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```
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## 235. 二叉搜索树的最近公共祖先
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[原题链接](https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-search-tree/)
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### 解一:递归
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分为几种情况:
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1. `p` 与 `q` 分列 `root` 节点两个子树,则直接返回 `root`
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2. `p` 与 `q` 其中之一等于 `root`,则直接返回 `root`
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3. 如果 `p` 和 `q` 都在 `root` 左子树,则递归左子树
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4. 如果 `p` 和 `q` 都在 `root` 右子树,则递归右子树
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<!-- tabs:start -->
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#### **Python**
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```python
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# Definition for a binary tree node.
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# class TreeNode:
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# def __init__(self, x):
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# self.val = x
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# self.left = None
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# self.right = None
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class Solution:
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def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
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if root is None:
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return root
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# 当前节点为 p 或 q
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if p.val == root.val or q.val == root.val:
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return root
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# 两个节点分别在左右两个子树
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if (p.val < root.val and q.val > root.val) or (p.val > root.val and q.val < root.val):
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return root
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# 两个节点都在左子树
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if p.val < root.val and q.val < root.val:
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return self.lowestCommonAncestor(root.left, p, q)
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# 两个节点都在右子树
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if p.val > root.val and q.val > root.val:
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return self.lowestCommonAncestor(root.right, p, q)
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```
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<!-- tabs:end -->
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### 解二:迭代
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@TODO
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## 236. 二叉树的最近公共祖先
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[原题链接](https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-tree/)(同 [面试题68 - II. 二叉树的最近公共祖先](https://leetcode-cn.com/problems/er-cha-shu-de-zui-jin-gong-gong-zu-xian-lcof/))

‎docs/offer/README.md‎

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*/
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```
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<!-- tabs:end -->
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<!-- tabs:end -->
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## 面试题68 - I. 二叉搜索树的最近公共祖先
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同:235. 二叉搜索树的最近公共祖先

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