/**
* 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 > q->val) swap(p, q);
if (!root) return nullptr;
// cout << root->val << endl;
if (p->val <= root->val && root->val <= q->val) return root;
if (p->val > root->val && q->val > root->val) {
return lowestCommonAncestor(root->right, p, q);
}
return lowestCommonAncestor(root->left, p, q);
}
};