Submission #1159226

#	Time	Username	Problem	Language	Result	Execution time	Memory
1159226		mendeke	Spring cleaning (CEOI20_cleaning)	C++20	9 / 100	1096 ms	19708 KiB

cleaning

//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include<bits/stdc++.h>
#define ll long long
#define F first
#define S second
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define all(x) x.begin(), x.end()

const int mod = 1e9 + 7;
const int N = 100001;

using namespace std;

ll n, q, m, a, b, c, d[N], cntleaves, p[N], used[N], cnt[N], ans, us[N];
vector <ll> g[N], dr, gl[N];
deque <pair <ll, ll>> sol;
deque <ll> st;

void dfs (ll v, ll pr){
	for (auto i: g[v]){
		if (i != pr){
			d[i] = d[v] + 1;
			dfs (i, v);
		}
	}
}

void ch (ll v, ll pr){
	for (auto i: g[v]){
		if (i != pr){
			ch (i, v);
			d[v] = max (d[v], d[i]);
		}
	}
}

void LT (ll v, ll pr, ll dep){
	d[v] = dep;
	if (g[v].size() == 1){
		st.pb (dep);
	}
	for (auto i: g[v]){
		if (i != pr){
			LT (i, v, dep + 1);
		}
	}
}

signed main (){
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	cin >> n >> q;
	for (int i = 1; i < n; i++){
		cin >> a >> b;
		g[a].pb (b);
		g[b].pb (a);
	}
	for (int i = 1; i <= n; i++){
		if (g[i].size() == 1){
			cntleaves++;
		}
	}
	d[1] = 1;
	dfs (1, 1);
	a = b = 0;
	for (int i = 1; i <= n; i++){
		if (a < d[i]){
			a = d[i];
			b = i;
		}
	}
	d[b] = 1;
	dfs (b, b);
	ch (b, b);
	st.pb (b);
	used[b] = 1;
	while (st.size()){
		a = st[0];
		dr.pb (a);
		st.ppf();
		for (auto i: g[a]){
			if (used[i] == 0 && d[i] == d[a]){
				st.pb (i);
				used[i] = 1;
				break;		
			}
		}
	}
	for (auto i: dr){
		d[i] = 0;
		for (auto j: g[i]){
			st.clear();
			if (used[j] == 0){
				LT (j, i, 1);
				for (auto y: st){
					gl[i].pb (y);
				}
			}
		}
	}
	for (int z = 1; z <= q; z++){
		cin >> m;
		a = 0;
		b = 0;
		for (int j = 1; j <= m; j++){
			cin >> p[j];
			if (g[p[j]].size() == 1){
				if (us[p[j]] == 0){
					us[p[j]] = 1;
					b++;
				}
				else{
					gl[p[j]].pb (d[p[j]] + 1);
					cnt[p[j]]++;
					b--;
				}
			}
			else{
				gl[p[j]].pb (1);
				cnt[p[j]]++;
				a++;
			}
		}
		for (int i = 1; i <= m; i++){
			us[p[i]] = 0;
		}
		if ((cntleaves + a) % 2){
			for (int i = 0; i < dr.size(); i++){
				while (cnt[i] > 0){
					cnt[i]--;
					gl[i].ppb();
				}
			}
			cout << "-1\n";
			continue;
		}
		ans = 0;
		ans += dr.size() - 1;
		sol.clear();
		for (int i = 0; i < dr.size(); i++){
			for (auto j: gl[dr[i]]){
				if (sol.size()){
					ans += sol[0].F + j + (i - sol[0].S);
					sol.ppf(); 
				}
				else{
					sol.pb ({j, i});
				}
			}
		}
		for (int i = 0; i < dr.size(); i++){
			while (cnt[i] > 0){
				cnt[i]--;
				gl[i].ppb();
			}
		}
		cout << ans + b << '\n';
	}
}

• Subtask 1: 0 / 0
• Subtask 2: 0 / 9
• Subtask 3: 9 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 17
• Subtask 7: 0 / 30