leetcode 235. 二叉搜索树的最近公共祖先
/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) { if(root==NULL || p==root || q==root) return root; if(root->val>p->val && root->val>q->val) return lowestCommonAncestor(root->left,p,q); if(root->val<p->val && root->val<q->val) return lowestCommonAncestor(root->right,p,q); return root; } };