oj.uz

Submission #1086126

# Submission time Handle Problem Language Result Execution time Memory
1086126 2024-09-09T15:39:09 Z _callmelucian Spring cleaning (CEOI20_cleaning) C++14
100 / 100
 127 ms 27540 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tt;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

pii refineTree (vector<vector<pii>> &graph, vector<int> &weight, vector<int> &node, int n, int root) {
    vector<int> vis(n + 1), deg(n + 1);
    queue<int> q;
    for (int i = 1; i <= n; i++)
        if (graph[i].size() == 1 && i != root) q.push(i);
    for (int u : node) deg[u] = 1;

    int ans = 0;
    while (q.size()) {
        int a = q.front(); q.pop();
        if (vis[a] == graph[a].size()) continue;
        vis[a]++;

        for (auto [b, id] : graph[a]) {
            if (vis[b] == graph[b].size()) continue;
            if (deg[a]) deg[b] ^= 1, ans += weight[id];
            else weight[id] = 0;

            if (++vis[b] + 1 == graph[b].size()) q.push(b);
        }
    }
    return {ans, (deg[root] == 0)};
}

const int mn = 1e5 + 5;
int up[mn][17], num[mn], sz[mn], dist[mn], depth[mn], timeDfs;
vector<vector<pii>> adj;
vector<int> weight;

void dfs (int u, int p, int d, int fromP) {
    dist[u] = dist[p] + fromP, num[u] = ++timeDfs, sz[u] = 1;
    up[u][0] = p, depth[u] = d;
    for (int i = 1; i < 17; i++)
        up[u][i] = up[up[u][i - 1]][i - 1];

    for (auto [v, id] : adj[u]) {
        if (v == p) continue;
        dfs(v, u, d + 1, weight[id]);
        sz[u] += sz[v];
    }
}

int goUp (int a, int k) {
    for (int i = 0; i < 17; i++)
        if (k & (1 << i)) a = up[a][i];
    return a;
}

int lca (int a, int b) {
    if (depth[a] < depth[b]) swap(a, b);
    a = goUp(a, depth[a] - depth[b]);
    if (a == b) return a;
    for (int i = 16; i >= 0; i--)
        if (up[a][i] != up[b][i]) a = up[a][i], b = up[b][i];
    return up[a][0];
}

int distance (int a, int b) {
    return dist[a] + dist[b] - 2 * dist[lca(a, b)];
}

int depthDist (int a, int b) {
    return depth[a] + depth[b] - 2 * depth[lca(a, b)];
}

bool check (int p, int u) {
    return num[p] <= num[u] && num[u] < num[p] + sz[p];
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    // setup graph
    int n, q; cin >> n >> q;
    adj.resize(n + 1), weight.resize(n);
    fill(all(weight), 1);

    for (int i = 1; i < n; i++) {
        int a, b; cin >> a >> b;
        adj[a].emplace_back(b, i);
        adj[b].emplace_back(a, i);
    }

    // find root
    int root = 0;
    vector<int> leaves;
    for (int i = 1; i <= n; i++)
        if (adj[i].size() == 1) root = i, leaves.push_back(i);

    // find initial answer
    int ans; bool correct; tie(ans, correct) = refineTree(adj, weight, leaves, n, root);
    dfs(1, 1, 0, 0);

    vector<bool> vis(n + 1);
    while (q--) {
        int d; cin >> d;

        map<int,int> mp;
        for (int i = 0; i < d; i++) {
            int node; cin >> node;
            mp[node]++;
        }
        if (!correct) mp[root]++;

        // create node list for virtual tree
        vector<int> qry, nodeList;
        for (auto [node, freq] : mp) {
            if (!correct && node == root && freq == 1) qry.push_back(node);
            else if (adj[node].size() == 1 && freq % 2 == 0) qry.push_back(node);
            else if (adj[node].size() > 1 && freq % 2) qry.push_back(node);
        }
        int sz = qry.size();
        for (int u : qry) vis[u] = 1;

        sort(all(qry), [&] (int a, int b) { return num[a] < num[b]; });
        for (int i = 1; i < sz; i++) {
            int tmp = lca(qry[i - 1], qry[i]);
            qry.push_back(tmp);
        }
        sort(all(qry), [&] (int a, int b) { return num[a] < num[b]; });
        filter(qry);

        for (int i = 0; i < qry.size(); i++) {
            if (vis[qry[i]]) nodeList.push_back(i + 1);
            vis[qry[i]] = 0;
        }

        // build virtual tree
        vector<vector<pii>> virtTree(qry.size() + 1);
        stack<int> st;
        vector<int> virtWeight;
        for (int i = 0; i < qry.size(); i++) {
            while (st.size() && !check(qry[st.top()], qry[i])) st.pop();
            if (st.size()) {
                int a = st.top() + 1, b = i + 1, c = depthDist(qry[st.top()], qry[i]) - 2 * distance(qry[st.top()], qry[i]), id = virtWeight.size();
                virtTree[a].emplace_back(b, id);
                virtTree[b].emplace_back(a, id);
                virtWeight.push_back(c);
            }
            st.push(i);
        }

        // find virtual tree's root
        int nroot = 0;
        for (int i = 1; i <= qry.size(); i++)
            if (virtTree[i].size() <= 1) nroot = i;

        int delta; bool curCorrect; tie(delta, curCorrect) = refineTree(virtTree, virtWeight, nodeList, qry.size(), nroot);
        int sumEdge = n + d - 1, oneEdge = ans + d + delta;

        //cout << "pre ans " << delta << " " << sumEdge << " " << oneEdge << "\n";
        if (curCorrect || qry.empty()) cout << 2 * sumEdge - oneEdge << "\n";
        else cout << -1 << "\n";
    }

    return 0;
}

Compilation message

cleaning.cpp: In function 'pii refineTree(std::vector<std::vector<std::pair<int, int> > >&, std::vector<int>&, std::vector<int>&, int, int)':
cleaning.cpp:23:20: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |         if (vis[a] == graph[a].size()) continue;
cleaning.cpp:26:19: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   26 |         for (auto [b, id] : graph[a]) {
      |                   ^
cleaning.cpp:27:24: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |             if (vis[b] == graph[b].size()) continue;
cleaning.cpp:31:30: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |             if (++vis[b] + 1 == graph[b].size()) q.push(b);
      |                 ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
cleaning.cpp: In function 'void dfs(int, int, int, int)':
cleaning.cpp:48:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   48 |     for (auto [v, id] : adj[u]) {
      |               ^
cleaning.cpp: In function 'int main()':
cleaning.cpp:121:19: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  121 |         for (auto [node, freq] : mp) {
      |                   ^
cleaning.cpp:137:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  137 |         for (int i = 0; i < qry.size(); i++) {
      |                         ~~^~~~~~~~~~~~
cleaning.cpp:146:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  146 |         for (int i = 0; i < qry.size(); i++) {
      |                         ~~^~~~~~~~~~~~
cleaning.cpp:159:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  159 |         for (int i = 1; i <= qry.size(); i++)
      |                         ~~^~~~~~~~~~~~~

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 42 ms 4380 KB Output is correct

Subtask #2
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 1628 KB Output is correct
2 Correct 10 ms 1476 KB Output is correct
3 Correct 32 ms 17740 KB Output is correct
4 Correct 50 ms 16332 KB Output is correct
5 Correct 73 ms 21448 KB Output is correct

Subtask #3
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 2396 KB Output is correct
2 Correct 12 ms 2396 KB Output is correct
3 Correct 40 ms 23372 KB Output is correct
4 Correct 81 ms 27536 KB Output is correct
5 Correct 38 ms 21192 KB Output is correct

Subtask #4
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 33 ms 5172 KB Output is correct
2 Correct 19 ms 4028 KB Output is correct
3 Correct 9 ms 3696 KB Output is correct
4 Correct 10 ms 4160 KB Output is correct
5 Correct 11 ms 4672 KB Output is correct
6 Correct 32 ms 4700 KB Output is correct

Subtask #5
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 52 ms 12108 KB Output is correct
2 Correct 71 ms 12272 KB Output is correct
3 Correct 49 ms 6740 KB Output is correct
4 Correct 62 ms 12372 KB Output is correct
5 Correct 65 ms 12364 KB Output is correct

Subtask #6
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 113 ms 17856 KB Output is correct
2 Correct 80 ms 21192 KB Output is correct
3 Correct 127 ms 19524 KB Output is correct
4 Correct 79 ms 20544 KB Output is correct

Subtask #7
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 42 ms 4380 KB Output is correct
3 Correct 11 ms 1628 KB Output is correct
4 Correct 10 ms 1476 KB Output is correct
5 Correct 32 ms 17740 KB Output is correct
6 Correct 50 ms 16332 KB Output is correct
7 Correct 73 ms 21448 KB Output is correct
8 Correct 12 ms 2396 KB Output is correct
9 Correct 12 ms 2396 KB Output is correct
10 Correct 40 ms 23372 KB Output is correct
11 Correct 81 ms 27536 KB Output is correct
12 Correct 38 ms 21192 KB Output is correct
13 Correct 33 ms 5172 KB Output is correct
14 Correct 19 ms 4028 KB Output is correct
15 Correct 9 ms 3696 KB Output is correct
16 Correct 10 ms 4160 KB Output is correct
17 Correct 11 ms 4672 KB Output is correct
18 Correct 32 ms 4700 KB Output is correct
19 Correct 52 ms 12108 KB Output is correct
20 Correct 71 ms 12272 KB Output is correct
21 Correct 49 ms 6740 KB Output is correct
22 Correct 62 ms 12372 KB Output is correct
23 Correct 65 ms 12364 KB Output is correct
24 Correct 113 ms 17856 KB Output is correct
25 Correct 80 ms 21192 KB Output is correct
26 Correct 127 ms 19524 KB Output is correct
27 Correct 79 ms 20544 KB Output is correct
28 Correct 65 ms 11128 KB Output is correct
29 Correct 81 ms 20380 KB Output is correct
30 Correct 60 ms 21448 KB Output is correct
31 Correct 74 ms 27540 KB Output is correct
32 Correct 68 ms 12108 KB Output is correct
33 Correct 103 ms 16600 KB Output is correct
34 Correct 97 ms 20288 KB Output is correct
35 Correct 101 ms 20288 KB Output is correct