Submission #1159078

#	Time	Username	Problem	Language	Result	Execution time	Memory
1159078		Kaztaev_Alisher	Spring cleaning (CEOI20_cleaning)	C++20	0 / 100	1096 ms	12356 KiB

cleaning

#include <bits/stdc++.h>

#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define all(a) a.begin() , a.end()
#define F first
#define S second

using namespace std;
using ll = long long;

const ll N = 2e5+5 , inf = 2e9 + 7;
const ll INF = 1e18 ,   mod = 1e9+7;

ll a[N] , b[N] , mx , par[N] , was[N]  , dp[N];
vector<int> g[N] , vec;
void dfs(int v, int p){
	dp[v] = dp[p]+1;
	par[v] = p;
	if(dp[v] > dp[mx]) mx = v;
	for(int to : g[v]){
		if(to != p){
			dfs(to,v);
		}
	}
}

void go(int v , int p){
	dp[v] = dp[p]+1;
	for(int to : g[v]){
		if(to != p && was[to] == 0){
			go(to,v);
		}
	}
	if(g[v].size() == 1){
		vec.push_back(dp[v]);
	}
}
void solve(){
	int n , q;
	cin >> n >> q;
	for(int i = 1; i < n; i++){
		cin >> a[i] >> b[i];
	}
	while(q--){
		int k;
		cin >> k;
		for(int i = 1; i <= n+k; i++) g[i].clear() , was[i] = par[i] = 0;
		for(int i = 1; i < n; i++){
			g[a[i]].push_back(b[i]);
			g[b[i]].push_back(a[i]);
		}
		for(int i = 1; i <= k; i++){
			int a;
			cin >> a;
			g[a].push_back(i+n);
			g[i+n].push_back(a);
		}
		mx = 1;
		dfs(1,0);
		dfs(mx,0);
		vector<int> path;
		while(mx > 0){
			path.push_back(mx);
			mx = par[mx];
		}
		reverse(all(path));
		ll cur = 0 ,  res = 0;
		for(int x : path) was[x] = 1;
		for(int x : path){
			for(int to : g[x]){
				if(was[to] == 0){
					vec.clear();
					dp[x] = 0;
					go(to,x);
					sort(all(vec));
					ll ans = 0;
					if(vec.size() % 2){
						ans = vec[0];
					} else {
						ans = vec[0]+vec[1];
					}
					res += vec.size();
					cur += ans;
				}
			}
		}
		if(res % 2) cout << "-1\n";
		else cout << cur+n-1 << "\n"; 
	}
}
/*

*/
signed main(){
	ios;
	solve();
}

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