Submission #1002362

#	Time	Username	Problem	Language	Result	Execution time	Memory
1002362		yoav_s	Spring cleaning (CEOI20_cleaning)	C++17	0 / 100	183 ms	26052 KiB

cleaning

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<ll> v;
typedef vector<v> vv;
typedef vector<vv> vvv;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<vvb> vvvb;
typedef pair<ll,ll> p;
typedef vector<p> vp;
typedef vector<vp> vvp;
typedef vector<vvp> vvvp;
typedef pair<ll, p> tri;
typedef vector<tri> vtri;
typedef vector<vtri> vvtri;
typedef vector<vvtri> vvvtri;

#define f first
#define s second
#define pb push_back
#define eb emplace_back
#define all(v) (v).begin(),(v).end()

const ll INF = 1e18;
const ll mod = 1e9 + 7;

ll getLeafCount(ll i, vv &graph, v &res)
{
    if (res[i] != -1) return 0;
    res[i] = 0;
    if (graph[i].size() == 1)
    {
        res[i] = 1;
        return 1;
    }
    for (ll x : graph[i]) res[i] += getLeafCount(x, graph, res);
    return res[i];
}

void getOddAndEvenParents(ll i, vv &graph, v &oddRes, v &evenRes, ll oddParents, ll evenParents, v &parity)
{
    if (oddRes[i] != -1) return;
    if (parity[i] % 2 == 0) evenParents++;
    else oddParents++;
    oddRes[i] = oddParents;
    evenRes[i] = evenParents;
    for (ll x : graph[i]) getOddAndEvenParents(x, graph, oddRes, evenRes, oddParents, evenParents, parity);
}

set<ll> solve(ll i, vv &graph, vb &visited, v &res, vv &changes, v &oddParents, v &evenParents)
{
    visited[i] = true;
    vector<set<ll>> childrenSets;
    for (ll x : graph[i])
    {
        if (visited[x]) continue;
        childrenSets.pb(solve(x, graph, visited, res, changes, oddParents, evenParents));
    }
    childrenSets.pb(set<ll>());
    for (ll x : changes[i]) childrenSets.back().insert(x);
    sort(all(childrenSets),[](set<ll> &a, set<ll> &b){return a.size() < b.size();});
    set<ll> baseSet;
    if (childrenSets.size() > 0)
    {
        baseSet = childrenSets.back();
        childrenSets.pop_back();
    }
    set<ll> newAdditions;

    for (auto &x : childrenSets)
    {
        for (auto y : x)
        {
            if (baseSet.count(y) > 0)
            {
                res[y] -= oddParents[i] - evenParents[i];
            }
            else
            {
                baseSet.insert(y);
                newAdditions.insert(y);
            }
        }
    }
    for (ll x : newAdditions) baseSet.erase(x);
    for (auto &x : childrenSets)
    {
        for (auto y : x)
        {
            if (baseSet.count(y) > 0)
            {
                baseSet.erase(y);
                res[y] += evenParents[i] - oddParents[i];
            }
            else
            {
                baseSet.insert(y);
                res[y] += oddParents[i] - evenParents[i];
            }
        }
    }
    return baseSet;
}

int main()
{
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    ll N, Q;
    cin >> N >> Q;
    vv graph(N);
    for (ll i = 0; i < N - 1; i++)
    {
        ll a, b;
        cin >> a >> b; a--; b--;
        graph[a].pb(b);
        graph[b].pb(a);
    }
    ll root = 0;
    while (graph[root].size() == 1) root++;
    v leafCount(N, -1);
    getLeafCount(root, graph, leafCount);
    v oddParents(N, -1), evenParents(N, -1);
    getOddAndEvenParents(root, graph, oddParents, evenParents, 0, 0, leafCount);
    vv queries(Q);
    for (ll i = 0; i < Q; i++)
    {
        ll amt;
        cin >> amt;
        for (ll j=  0; j < amt; j++)
        {
            ll par;
            cin >> par;
            par--;
            queries[i].pb(par);
        }
    }
    vv changedInQueries(N);
    for (ll i = 0 ;i < Q; i++)
    {
        map<ll, ll> changed;
        
        for (ll x : queries[i])
        {
            changed[x]++;
        }
        for (auto x : changed)
        {
            if ((x.s % 2 == 1) ^ (graph[x.f].size() == 1)) changedInQueries[x.f].pb(i);
        }
    }
    v addToQuery(Q);
    ll base = N - 2;
    for (ll i = 0 ;i < N; i++) if (leafCount[i] % 2 == 0) base++;
    vb visited(N, false);
    solve(root, graph, visited, addToQuery, changedInQueries, oddParents, evenParents);
    for (ll i = 0; i < Q; i++)
    {
        ll count = leafCount[root] + queries[i].size();
        set<ll> changed;
        for (ll x : queries[i]) if (graph[x].size() == 1) changed.insert(x);
        count -= changed.size();
        if (count % 2 == 1) cout << "-1\n";
        else cout << base + queries[i].size() + addToQuery[i] << "\n";
    }
    return 0;
}

• 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