This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
int sol,nrsol=INT_MAX,n,m;
long long vr[30];
void bec(long long mcarti, int act, int mvraji, int nrvraja)
{
    if(act==m)
    {
        if(mcarti==(1<<n)-1)
        {
            if(nrsol>nrvraja)
            {
                nrsol=nrvraja;
                sol=mvraji;
            }
        }
        return ;
    }
    bec(mcarti^vr[act],act+1,mvraji^(1<<act),nrvraja+1);
    bec(mcarti,act+1,mvraji,nrvraja);
}
int main()
{
    //freopen("norela.in","r",stdin);
    //freopen("norela.out","w",stdout);
    cin.sync_with_stdio(false);
    cin.tie(0);
    cin>>n>>m;
    for(int i=0; i<m; ++i)
    {
        int q;
        cin>>q;
        for(int j=0; j<q; ++j)
        {
            int x;
            cin>>x;
            x--;
            vr[i]^=(1LL<<(x));
        }
    }
    bec(0,0,0,0);
    cout<<nrsol<<'\n';
    for(int i=0; i<=m-1; ++i)if(sol&(1<<i))cout<<i+1<<" ";
    cout<<'\n';
    return 0;
}
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... |