Submission #1043679

#	Time	Username	Problem	Language	Result	Execution time	Memory
1043679		beaconmc	Spring cleaning (CEOI20_cleaning)	C++14	9 / 100	1073 ms	15560 KiB

cleaning

#include <bits/stdc++.h>
 
typedef long long ll;
#define FOR(i,x,y) for(ll i=x; i<y; i++)
#define FORNEG(i,x,y) for(ll i=x; i>y; i--)
 
using namespace std;

vector<ll> edges[200005];
ll realans = 0;
ll vals[200005];
ll origvals[200005];
ll par[200005];

int dp(ll a, ll p){

	par[a] = p;
	ll ans = 0;
	if (edges[a].size() <= 1) ans = 1;
	for (auto&i : edges[a]){
		if (i != p) ans += dp(i, a);
	}		
	if (p!=-1) realans += 1 + (ans+1)%2;

	if (p != -1) vals[a] = 1 + (ans+1)%2;

	origvals[a] = 1 + (ans+1)%2;

	return 1 + (ans+1)%2;
}
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	ll n,q;
	cin >> n >> q;
	FOR(i,0,n-1){
		ll a,b;
		cin >> a >> b;
		edges[a].push_back(b);
		edges[b].push_back(a);
	}
	ll root = -1;
	ll cnt = 0;
	FOR(j,1,n+1){
		if (edges[j].size() != 1){
			root = j;
		}else{
			cnt++;
		}
	}
	dp(root, -1);
	ll ans = 0;
	FOR(i,1,n+1) ans += vals[i];
	

	FOR(i,0,q){
		ll d; cin >> d;
		ll cur = n+1;
		ll curans = 0;
		set<ll> used;
		ll newleaves=0;

		FOR(k,0,d){
			ll temp; cin >> temp;
			if (edges[temp].size() != 1){
				newleaves++;
				curans+= 1;
				ll idk = temp;
				while (idk != root){
					used.insert(idk);
					if (vals[idk]==1) curans += 1, vals[idk]=2;
					else curans -= 1, vals[idk] = 1;
					idk = par[idk];
				}
			}else{
				curans += 1;
			}
			edges[temp].push_back(cur++);
		}


		for (auto&k : used){
			vals[k] = origvals[k];
		}


		if ((cnt+newleaves)%2==1) cout << -1 << "\n";
		else{
			cout << ans+curans << "\n";
		}
		FOR(i,1,n+1){
			while (edges[i].size() && edges[i][edges[i].size()-1]>n){
				edges[i].pop_back();
			}
		}

	}
}

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