제출 #440010

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
440010		kekw_orz	Spring cleaning (CEOI20_cleaning)	C++14	34 / 100	1092 ms	34376 KiB

cleaning

// ¯\_(ツ)_/¯
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;

#define all(x)                      (x).begin(),(x).end()
#define X                           first
#define Y                           second
#define sep                         ' '
#define endl                        '\n'
#define debug(x)                    cerr << #x << ": " <<  x << endl;

const ll MAXN = 1e6 + 10;
const ll INF = 8e18;
const ll MOD = 1e9 + 7; // 998244353; // 1e9 + 9;

int n, q, sub_g[MAXN], r;
ll ans = 0;
vector<int> adj[MAXN];

void dfs(int v, int p) {
	if (adj[v].size() <= 1) {
		ans++;
		sub_g[v] = 1;
		return;
	}

	for (int u : adj[v]) {
		if (u == p) continue;
		dfs(u, v);
		sub_g[v] += sub_g[u];
	}

	if (v == r) return;
	if (sub_g[v] & 1) ans++;
	else ans += 2;
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> n >> q;
	for (int i = 1; i < n; i++) {
		int u, v;
		cin >> u >> v;
		adj[v].push_back(u);
		adj[u].push_back(v);

		if (adj[v].size() > 1) r = v;
		if (adj[u].size() > 1) r = u;
	}
	
	while (q--) {
		int k;
		cin >> k;

		int t = n + 1;
		for (int i = 0; i < k; i++) {
			int v;
			cin >> v;
			adj[v].push_back(t++);
		}

		ans = 0;
		dfs(r, 0);
		cout << (sub_g[r] % 2 == 0 ? ans : -1) << endl;
		
		for (int i = 1; i <= t + 10; i++) {
			while (!adj[i].empty() && adj[i].back() > n)
				adj[i].pop_back();
			sub_g[i] = 0;
		}

	}
	return 0;
}

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