Submission #1150748

#	Time	Username	Problem	Language	Result	Execution time	Memory
1150748		vladilius	Spring cleaning (CEOI20_cleaning)	C++20	100 / 100	210 ms	19012 KiB

cleaning

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second

struct ST{
    vector<int> t;
    vector<bool> p;
    int n;
    ST(int ns){
        n = ns;
        t.resize(4 * n);
        p.resize(4 * n);
    }
    void push(int v, int tl, int tr){
        if (!p[v]) return;
        int vv = 2 * v, tm = (tl + tr) / 2;
        t[vv] = (tm - tl + 1) - t[vv];
        t[vv + 1] = (tr - tm) - t[vv + 1];
        p[vv] = !p[vv]; p[vv + 1] = !p[vv + 1];
        p[v] = 0;
    }
    void upd(int v, int tl, int tr, int l, int r){
        if (l > tr || r < tl) return;
        if (l <= tl && tr <= r){
            p[v] = !p[v];
            t[v] = (tr - tl + 1) - t[v];
            return;
        }
        int tm = (tl + tr) / 2, vv = 2 * v;
        push(v, tl, tr);
        upd(vv, tl, tm, l, r);
        upd(vv + 1, tm + 1, tr, l, r);
        t[v] = t[vv] + t[vv + 1];
    }
    void upd(int l, int r){
        upd(1, 1, n, l, r);
    }
    int get(){
        return t[1];
    }
};

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n, q; cin>>n>>q;
    vector<int> g[n + 1];
    for (int i = 1; i < n; i++){
        int u, v; cin>>u>>v;
        g[u].pb(v);
        g[v].pb(u);
    }
    
    vector<int> sz(n + 1), h(n + 1), p(n + 1);
    function<void(int, int)> fill = [&](int v, int pr){
        sz[v] = 1; p[v] = pr;
        for (int i: g[v]){
            if (i == pr) continue;
            fill(i, v);
            sz[v] += sz[i];
            if (sz[i] > sz[h[v]]){
                h[v] = i;
            }
        }
    };
    fill(1, 0);
    
    vector<int> pos(n + 1), head(n + 1);
    int timer = 0;
    function<void(int, int)> fill_hld = [&](int v, int k){
        pos[v] = ++timer; head[v] = k;
        if (!h[v]) return;
        fill_hld(h[v], k);
        for (int i: g[v]){
            if (!pos[i]){
                fill_hld(i, i);
            }
        }
    };
    fill_hld(1, 1);
    
    vector<int> f(n + 1);
    ST T(n);
    auto upd = [&](int v){
        f[1] = !f[1];
        while (v > 0){
            T.upd(pos[head[v]], pos[v]);
            v = p[head[v]];
        }
    };
    
    int lf = 0;
    for (int i = 1; i <= n; i++){
        if (g[i].size() == 1){
            upd(i);
            lf++;
        }
    }
    
    vector<bool> used(n + 1);
    vector<int> v;
    while (q--){
        int d; cin>>d;
        vector<int> a(d + 1);
        int cc = lf + d;
        for (int i = 1; i <= d; i++){
            cin>>a[i];
            if (g[a[i]].size() > 1) continue;
            if (!used[a[i]]){
                cc--;
                used[a[i]] = 1;
            }
        }
        
        if (cc % 2){
            cout<<-1<<"\n";
            for (int i = 1; i <= d; i++){
                used[a[i]] = 0;
            }
            continue;
        }
        
        v.clear();
        int out = d;
        for (int i = 1; i <= d; i++){
            if (used[a[i]]){
                used[a[i]] = 0;
                continue;
            }
            upd(a[i]);
            v.pb(a[i]);
        }
        
        int k = T.get() - f[1];
        out += (k + (n - k - 1) * 2);
        
        cout<<out<<"\n";
        
        for (int i: v){
            upd(i);
        }
    }
}

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