题解 | #二叉搜索树的最近公共祖先#

using System;
using System.Collections.Generic;

/*
public class TreeNode
{
	public int val;
	public TreeNode left;
	public TreeNode right;

	public TreeNode (int x)
	{
		val = x;
	}
}
*/

class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param root TreeNode类 
     * @param p int整型 
     * @param q int整型 
     * @return int整型
     */
    public int lowestCommonAncestor (TreeNode root, int p, int q) {
        int big = Math.Max(p,q);
        int small = Math.Min(p,q);
        TreeNode cur = root;
        while(cur != null){
            if(small == cur.val || big == cur.val) return cur.val;
            if(small < cur.val){
                if(big > cur.val) return cur.val;
                cur = cur.left;
            }
            else{
                cur = cur.right;
            }

        }
        return -1;
    }
}