美团 4.23笔试第五题 整数相与

如题。暴力做法，过了45%，超时。我不记得题目中输入数据是否包含负数了。现在想到优化的思路就是建树。测了几个样例是对的。但是现在没法跑后台数据了。还有其它思路不？

import java.util.*;
public class test {
    static class Node{
        Node left;
        Node right;
        int val;
        Node(int val)
        {
            this.val = val;
        }
    }
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while(in.hasNext())
        {
            int N = in.nextInt();
            int[] arr = new int[N];
            Node root = new Node(-1);
            for(int i=0;i<N;i++)
            {
                arr[i] = in.nextInt();
                createTree(root, arr[i], 0);
            }
            boolean[] flag = new boolean[N];
            for(int i=0;i<N;i++)
            {
                if(find(root, arr[i], 0))
                    flag[i] = true;
            }
            for (int i = 0; i < N; i++) {
                String s = (flag[i]?1:-1)+" ";
                System.out.print(s);
            }
        }
    }
    public static boolean find(Node root, int num, int depth)
    {
        if(root==null)
        {
            if(depth<33)
                return false;
            else if(depth==33)
                return true;
        }
        int val = num%2;
        int next=num/2;
        if(val==0)
        {
            return find(root.left, next, depth+1)||find(root.right, next, depth+1);
        }
        else
        {
            return find(root.left, next, depth+1);
        }
    }
    public  static void  createTree(Node root, int num, int depth)
    {
        if(depth>=32)
            return;
        int val = num%2;
        int next = num/2;
        if(val==0)
        {
            if(root.left==null)
            {
                Node left = new Node(0);
                root.left = left;
            }
            createTree(root.left, next, depth+1);
        }
        else
        {
            if(root.right==null)
            {
                Node right = new Node(1);
                root.right = right;
            }
            createTree(root.right, next, depth+1);
        }
    }
}