Шаг в буд_Отбор_N6

#include <iostream>
#include <cmath>
#include <vector>
#include <set>
#include <string>
#include <algorithm>
using namespace std;
using ll = long long;
void co(vector <int> v){
    for (auto x: v) cout<<x<<' ';
    cout<<'\n';
}

int main()
{
    int n;
    cin>>n;
    int R;
    cin>>R;
    vector <int> r(n);
    for (int &x: r) cin>>x;
    int ans = 0;
    //vector <int> now;
    //vector <vector <int> > all;
    for (int mask = 0; mask < (1 << n); mask++) {
        //now.clear();
        int Ri = 0;
        for (int i = 0; i < n; ++i) {
            if (mask & (1 << i)) {
                //cout << 1;
                Ri += r[i];
                //now.push_back(r[i]);
            }
            /*else {

                //cout << 0;
            }*/
        }//cout << '\n';
        if (Ri == R) {
                ans++;
                //all.push_back(now);
                //co(now);
                //cout<<"YES"<<endl;
        }
    }
    /*
    cout<<'\n';
    co(r);
    cout<<"all\n";
    for (auto x: all) co(x);
    cout<<"ans = ";*/
    cout<<ans;
}