Submission #217511

#	Time	Username	Problem	Language	Result	Execution time	Memory
217511		dimash241	Norela (info1cup18_norela)	C++17	100 / 100	7 ms	640 KiB

norela

//#pragma GCC target("avx2")
//#pragma GCC optimize("O3")

//# include <x86intrin.h>
# include <bits/stdc++.h>

//# include <ext/pb_ds/assoc_container.hpp>
//# include <ext/pb_ds/tree_policy.hpp>

//using namespace __gnu_pbds;
using namespace std;
 
//template<typename T> using ordered_set = tree <T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define _USE_MATH_DEFINES_
#define ll long long
#define ld long double
#define Accepted 0
#define pb push_back
#define mp make_pair
#define sz(x) (int)(x.size())
#define every(x) x.begin(),x.end()
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define For(i,x,y)  for (ll i = x; i <= y; i ++) 
#define FOr(i,x,y)  for (ll i = x; i >= y; i --)
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
// ROAD to...                                                                                                                                                                                                                Red

inline void Input_Output () {
	//freopen(".in", "r", stdin);
   //freopen(".out", "w", stdout);
}

const double eps = 0.000001;
const ld pi = acos(-1);
const int maxn = 1e7 + 9;
const int mod = 1e9 + 7;
const ll MOD = 1e18 + 9;
const ll INF = 1e18 + 123;
const int inf = 2e9 + 11;
const int mxn = 1e6 + 9;
const int N = 6e5 + 123;                                          
const int M = 22;
const int pri = 997;
const int Magic = 2101;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};
 
int n, m;
vector < int > g[33];
ll mo[33];
map < ll, int > d;

int bit_count (ll x) {
	return __builtin_popcountll(x);
}



int main () {
	SpeedForce;
	cin >> n >> m;
	for (int i = 0, cur; i < m; ++i) {
		cin >> cur;
		g[i].resize(cur);
		for (auto &e : g[i]) {
			cin >> e;
			--e;
			mo[i] |= (1ll<<e);
		}
	}

	int m1 = m / 2, m2 = m - m1;
	for (int msk = 0; msk < (1<<m1); msk++) {
		ll bit = 0;
		for (int i = 0; i < m1; ++i) {
			if (msk & (1 << i)) {
				bit ^= mo[i];
			}
		}
		if(!d.count(bit) || bit_count(msk) < bit_count(d[bit]))
			d[bit] = msk;
	}
	ll ans = (1ll << m) -1;
	vector < int > res;
	for (ll msk = 0; msk < (1<<m2); msk++) {
		ll bit = 0;
		for (int i = 0; i < m2; ++i) {
			if (msk & (1 << i)) {
				bit ^= mo[i+m1];
			}
		}
		ll rev = (1ll<<n)-1;
		rev ^= bit;
		if(d.count(rev)) {
			ll now = d[rev] | (msk<<m1);
			vector < int > cur;
			for (int i = 0; i < m; ++i) {
				if(now & (1ll << i)) {
					cur.pb(i);
				}	
			}
			if(res.empty() || bit_count(ans) > bit_count(now)) {	
				ans = now;
				res = cur;
			} else if (bit_count(ans) == bit_count(now)) {
				if(res > cur) {
					ans = now;
					res = cur;
				}
			}

		}
	}

	assert(res.size()>0);
	cout << sz(res) << '\n';
	for (auto it : res)
		cout << it+1 << ' ';
	cout << '\n';

	return Accepted;
}

// B...a

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