判断一颗树是否为二叉搜索树及完全二叉树

递归套路，主要是分解信息和合并左右子树需要提供的信息。
当前节点是完全二叉树条件：左子树为完全二叉树 右子树也为完全二叉树 且 左树为空时右树必须为空
当前节点是二叉搜索树条件：左右子树都为搜索树 且 左树根节点值及其根节点右节点都小于当前节点。右树同理
上代码：

import java.util.*;

/*
 * public class TreeNode {
 *   int val = 0;
 *   TreeNode left = null;
 *   TreeNode right = null;
 * }
 */

public class Solution {
    /**
     * 
     * @param root TreeNode类 the root
     * @return bool布尔型一维数组
     */
    public boolean[] judgeIt (TreeNode root) {
        // write code here
        if(root==null){
           return new boolean[]{false,false};
        }
        Info result=judgeItInfo(root);
        return new boolean[]{result.isSearch,result.isAll};
    }
    class Info{
        boolean isSearch;
        boolean isAll;
        Integer val;
        Integer leftVal;
        Integer rightVal;
        Info(boolean isSearch,boolean isAll,Integer val,Integer leftVal,Integer rightVal){
            this.isSearch=isSearch;
            this.isAll=isAll;
            this.val=val;
            this.leftVal=leftVal;
            this.rightVal=rightVal;
        }
    }

    public Info judgeItInfo(TreeNode root){

        if(root==null){
            return new Info(true,true,null,null,null);
        }

        Info leftInfo=judgeItInfo(root.left);
        Info rightInfo=judgeItInfo(root.right);
        boolean isSearch=leftInfo.isSearch&&rightInfo.isSearch;
        boolean isAll=leftInfo.isAll&&rightInfo.isAll;
        //左节点为空 右节点不为空 则不是完全二叉树
        if(leftInfo.val==null&&rightInfo.val!=null){
            isAll=false;
        }
        //判断是否为搜索树时注意 左右子树的左右子树也需要跟根节点比较
        if(leftInfo.val!=null){
            isSearch=isSearch&&leftInfo.val<=root.val;
            if(leftInfo.rightVal!=null){
                 isSearch=isSearch&&leftInfo.rightVal<=root.val;
            }
        }

        if(rightInfo.val!=null){
            isSearch=isSearch&&rightInfo.val>=root.val;
            if(rightInfo.leftVal!=null){
                 isSearch=isSearch&&rightInfo.leftVal>=root.val;
            }
        }
        return new Info(isSearch,isAll,root.val,root.left==null?null:root.left.val,root.right==null?null:root.right.val);

    }

}