二叉搜索树的最近公共祖先 (Lowest Common Ancestor of a Binary Search Tree)

思路:

// @Title: 二叉搜索树的最近公共祖先 (Lowest Common Ancestor of a Binary Search Tree)
// @Author: qisiii
// @Date: 2024-09-16 17:11:25
// @Runtime: 6 ms
// @Memory: 43.8 MB
// @comment: 
// @flag: 
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */

class Solution {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        if(root==null||root==p||root==q){
            return root;
        }
        if(root.val>p.val&&root.val>q.val){
           return lowestCommonAncestor(root.left,p,q);
        }else if(root.val<p.val&&root.val<q.val){
            return lowestCommonAncestor(root.right,p,q);
        }else{
            return root;
        }
    }
}

思路:

// @Title: 二叉搜索树的最近公共祖先 (Lowest Common Ancestor of a Binary Search Tree)
// @Author: qisiii
// @Date: 2024-09-16 17:14:07
// @Runtime: 6 ms
// @Memory: 43.8 MB
// @comment: 
// @flag: 
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */

class Solution {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        if(root.val>p.val&&root.val>q.val){
           return lowestCommonAncestor(root.left,p,q);
        }else if(root.val<p.val&&root.val<q.val){
            return lowestCommonAncestor(root.right,p,q);
        }else{
            return root;
        }
    }
}