LeetCode 面试题68-I. 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) {
        while(root){
            if(p->val<root->val&&q->val<root->val){
                root=root->left;
            }
            else if(p->val>root->val&&q->val>root->val){
                root=root->right;
            }
            else{
                return root;
            }
        }
        return root;
    }
};