Submission #888282

#	Time	Username	Problem	Language	Result	Execution time	Memory
888282		SzypkiBill	Spring cleaning (CEOI20_cleaning)	C++17	0 / 100	1083 ms	10472 KiB

cleaning

#include <bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define all(x) x.begin(),x.end()
#define vi vector<int>
#define vii vector<pii>
#define siz(x) (int)x.size()
#define pb push_back
#define rep(i,x) for(int i=0; i<x; i++)
#define rep1(i,x) for(int i=1; i<=x; i++)
using namespace std;
const int inf = 1e9, maxn = 1e5+5, mod = 1e9+7;
int n,q,ileparzystych;

int liscie[maxn];
bool parzyste[maxn];
int parent[maxn];
vi graf[maxn];

void DFS(int v, int p){
    parent[v] = p;
    if(siz(graf[v])==1)liscie[v] = 1;
    for(auto u:graf[v])if(u!=p){
        DFS(u,v);
        liscie[v]+=liscie[u];
    }
    parzyste[v] = !(liscie[v]%2);
    if(parzyste[v] && v!=1)ileparzystych++;
}

int32_t main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    cin>>n>>q;
    rep(i,n-1){
        int a,b;
        cin>>a>>b;
        graf[a].pb(b);
        graf[b].pb(a);
    }
    DFS(1,0);

    rep(i,q){
        int d;
        cin>>d;
        vi a(d);
        int dojeden = 0;
        rep(j,d){
            cin>>a[j];
            if(a[j]==1){
                dojeden++;
                continue;
            }
            int x = a[j];
            while(x>1){
                parzyste[x] = !parzyste[x];
                if(parzyste[x])ileparzystych++;
                else ileparzystych--;
                x = parent[x];
            }
        }
        if((ileparzystych+dojeden)&1)cout<<-1<<'\n';
        else cout<<n-1+d+ileparzystych<<'\n';
        rep(j,d){
            int x = a[j];
            if(a[j]==1){
                dojeden--;
                continue;
            }
            while(x>1){
                parzyste[x] = !parzyste[x];
                if(parzyste[x])ileparzystych++;
                else ileparzystych--;
                x = parent[x];
            }
        }
    }

}

• 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