Submission #1134215

#	Time	Username	Problem	Language	Result	Execution time	Memory
1134215		bpptidp	Norela (info1cup18_norela)	C++20	100 / 100	80 ms	528 KiB

norela

#include<iostream>
using namespace std;

using ll=long long;
ll c[26],x,pc2;
int ans,nw,msk,cans;
int n,m;

void r(int i){
	if(i>=m){
		if(!x){
    		int pc1=cans;
    		if(pc1<pc2)return;
    		if(pc1>pc2){ans=nw;cans=pc2;}
    		else ans=max(ans,nw);
    	}
    	return;
	}
	r(i+1);
	x^=c[i];
	msk^=(1<<i);
	nw^=(1<<(m-i-1));
	++pc2;
	r(i+1);
	msk^=(1<<i);
	nw^=(1<<(m-i-1));
	x^=c[i];
	--pc2;
}

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);

    cin>>n>>m;

    for(int i=0,q,x;i<m;++i){
    	cin>>q;
    	while(q--){
    		cin>>x;
    		c[i]|=(1ll<<(x-1));
    	}
    }

    for(int i=0;i<n;++i)
    	x|=(1ll<<i);

    cans=m;
    for(int j=0;j<m;++j)
    	ans|=(1<<(j));

    r(0);

    cout<<cans<<'\n';
    for(int i=m-1;~i;--i)
    	if(ans&(1<<i))cout<<m-i<<' ';
}

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 25 / 25
• Subtask 4: 25 / 25