一、题目内容

二、题解

解法1：

思路

代码

迭代法

class Solution {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        while(root != null){
            if(root.val<p.val && root.val<q.val){ //都在右子树
                root = root.right;
            }
            else if(root.val>p.val && root.val>q.val){//都在左子树
                root = root.left;
            }
            else{
                break;
            }
        }
        return root;
    }
}

递归法

class Solution {
    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
        if(root.val<p.val && root.val<q.val){ //都在右子树
            return lowestCommonAncestor(root.right,p,q);
        }else if(root.val>p.val && root.val>q.val){//都在左子树
            return lowestCommonAncestor(root.left,p,q);
        }else{
            return root;
        }
    }
}