The 2018 ACM-ICPC Asia Qingdao Regional Contest K XOR Clique

K XOR Clique

BaoBao has a sequence a​1​​,a​2​​,...,a​n​​. He would like to find a subset S of {1,2,...,n} such that ∀i,j∈S, a​i​​⊕a​j​​<min(a​i​​,a​j​​) and ∣S∣ is maximum, where ⊕ means bitwise exclusive or.

Input

There are multiple test cases. The first line of input contains an integer T, indicating the number of test cases. For each test case:

The first line contains an integer n (1≤n≤10​5​​), indicating the length of the sequence.

The second line contains n integers: a​1​​,a​2​​,...,a​n​​ (1≤a​i​​≤10​9​​), indicating the sequence.

It is guaranteed that the sum of n in all cases does not exceed 10​5​​.

Output

For each test case, output an integer denoting the maximum size of S.

Sample Input

3
3
1 2 3
3
1 1 1
5
1 2323 534 534 5

Sample Output

2
3
2


给出n个数字，要求输出一个最长集合的长度，在这个集合中任意两个数两两异或后结果比原来小
相当于集合中每个数的二进制形式长度相等

#include<bits/stdc++.h>
using namespace std;
int s[3000];
int bit_width(unsigned int n)
{
    unsigned int i = 0;
 
    do {
        ++i;
    } while ((n >> i));
 
    return i;
}
int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        int n,a;
        scanf("%d",&n);
        memset(s,0,sizeof(s));
        int len1,len2,num=0,maxx=0;
        for(int i=0;i<n;i++)
        {
            scanf("%d",&a);
            len1=bit_width(a);
            s[len1]++;
            
        }    
        for(int i=0;i<3000;i++)
        {
            maxx=max(maxx,s[i]);
        }
        printf("%d
",maxx);
    }
    return 0;
}