Submission #1282873

#	Time	Username	Problem	Language	Result	Execution time	Memory
1282873		TVSown	Spring cleaning (CEOI20_cleaning)	C++20	34 / 100	1097 ms	33304 KiB

cleaning

///*** Sown_Vipro ***///
/// ->TEAM SELECTION TEST<- ///

#include<bits/stdc++.h>
using namespace std;
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("popcnt")
#define F first
#define S second
#define pb push_back
#define pi pair<int, int>
#define pii pair<int, pair<int, int> >
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define REP(i, a, b) for(int i = a; i >= b; --i)
#define all(s) s.begin(), s.end()
#define szz(s) int(s.size())
const string NAME = "sown";
const int N = 1e6 + 5, MAX = 1e6, MOD = 1e9 + 7;
void maxi(int &x, int y){ if(x < y) x = y; }
void mini(int &x, int y){ if(x > y) x = y; };
void add(int &x, int y){ x += y; x += MOD * (x < 0); x -= MOD * (x >= MOD); };
int n, q, res;
int p[20][N], h[N], a[N];
vector<int> e[N];

void pre(int u){
    h[u] = h[p[0][u]] + 1;
    for(int v : e[u]){
        if(v == p[0][u]) continue;
        p[0][v] = u;
        pre(v);
    }
}

int lca(int u, int v){
    if(h[u] < h[v]) swap(u, v);
    REP(k, 18, 0){
        int pu = p[k][u];
//        cout << u << " " << k << " " << pu << "\n";
        if(h[pu] >= h[v]) u = pu;
    }
    if(u == v) return u;
    REP(k, 18, 0){
        int pu = p[k][u], pv = p[k][v];
//        cout << pu << " " << pv << "\n";
        if(pu != pv){
            u = pu;
            v = pv;
        }
    }
    return p[0][u];
}

int dist(int u, int v){
    int w = lca(u, v);
//    cout << w << "\n";
    return h[u] + h[v] - 2 * h[w];
}

pair<int, int> dfs(int u, int p){
    pair<int, int> c, d;

    if(e[u].size() == 1){
        c = {u, 0};
    }

    for(int v : e[u]){
        if(v == p) continue;

        d = dfs(v, u);
        if(!c.F){
            c = d;
            continue;
        }
        if(c.S){
            if(d.S){
//                cout << c.S << " " << d.S << "\n";
                res += dist(c.S, d.S);
                c.S = d.F;
            }else{
//                cout << c.S << " " << d.F << "\n";
                res += dist(c.S, d.F);
                c.S = 0;
            }
        }else{
            if(d.S){
//                cout << c.F << " " << d.S << "\n";
                res += dist(c.F, d.S);
                c.F = d.F;
            }else c.S = d.F;
        }
    }
//    cout << u << " " << c.F << " " << c.S << " " << res << "\n";
    return c;
}

void solve(){
    cin >> n >> q;
    FOR(i, 2, n){
        int u, v; cin >> u >> v;
        e[u].pb(v);
        e[v].pb(u);
    }


    FOR(i, 1, q){
        int s; cin >> s;
        FOR(i, 1, s){
            cin >> a[i];
            e[a[i]].pb(i + n);
            e[i + n].pb(a[i]);
//            cout << a[i] << " " << i + n << "\n";
        }
        pre(1);
        FOR(k, 1, 18) FOR(u, 1, n + s) p[k][u] = p[k - 1][p[k - 1][u]];
//        cout << dist(7, 3) << "\n";
        res = 0;
        pair<int, int> c = dfs(1, 0);
        FOR(i, 1, s){
            e[a[i]].pop_back();
            e[i + n].pop_back();
        }
        if(c.F && c.S){
            res += dist(c.F, c.S);
            c.F = c.S = 0;
        }
        if(c.F){
            cout << -1 << "\n";
            continue;
        }
        cout << res << "\n";
    }
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    if(fopen((NAME + ".inp").c_str(), "r")){
        freopen((NAME + ".inp").c_str(), "r", stdin);
//        freopen((NAME + ".out").c_str(), "w", stdout);
    }
    int t = 1;
//    cin >> t;
    while(t--){
        solve();
    }
}

Compilation message (stderr)

cleaning.cpp: In function 'int main()':
cleaning.cpp:140:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  140 |         freopen((NAME + ".inp").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• 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