题意:判断BST中两个节点的最近的公共父节点
题解:递归的时候判断如果两个节点的值在父节点两边,那个这个父节点就是最近的公共父节点。否则按照二叉搜索树的规则递归下去。
/**
* 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(p->val<=root->val&&q->val>=root->val)
return root;
if(p->val>=root->val&&q->val<=root->val)
return root;
if(p->val<root->val&&q->val<root->val)
return lowestCommonAncestor(root->left,p,q);
return lowestCommonAncestor(root->right,p,q);
}
};