subset.cpp

#include <iostream>
#include <numeric>
#include <vector>
#include <functional>
#include<algorithm>
using std::vector;

void max_subset(const vector<int>& A,
                 vector<int>& curr_set,
                 int index,
                 unsigned& result)
{
        if(result==A.size()) return;

    if(std::accumulate(curr_set.begin(), curr_set.end(),-1,std::bit_and<int>()) > 0 && result < curr_set.size())
        result=curr_set.size();


    for (int i = index; i < A.size(); i++) {

        curr_set.push_back(A[i]);

        max_subset(A, curr_set, i + 1, result);

        curr_set.pop_back();
    }

}

int solution(const vector<int>& A){

    vector<int> sub_set;
    int index=0;
    unsigned res=0;

    max_subset(A, sub_set, index , res);
        return res;
}

int main()
{
    vector<int> array = {16,16};


    std::cout<<solution(array);
    return 0;
}