Submission #1093626

#	Time	Username	Problem	Language	Result	Execution time	Memory
1093626		CDuong	Inside information (BOI21_servers)	C++17	57.50 / 100	263 ms	32748 KiB

servers

/*
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,fma,bmi,bmi2,sse4.2,popcnt,lzcnt")
*/

#include <bits/stdc++.h>
#define taskname ""
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define i64 long long
#define isz(x) (int)x.size()
using namespace std;

mt19937 rng(177013);
mt19937_64 rngll(chrono::high_resolution_clock::now().time_since_epoch().count());
using randint_t = uniform_int_distribution<int>;
using randll_t = uniform_int_distribution<long long>;
using randd_t = uniform_real_distribution<double>;
// return x with probability p, y with probability 1-p
template<class T>
T pick(T x, T y, double p = 0.5){
    assert(-0.0001 <= p && p <= 1.0001);
    return randd_t(0, 1)(rng) <= p ? x : y;
}
array<int, 2> gen_range(int n, bool allow_empty_range = false){
    if(allow_empty_range){
        int l = rng() % (n + 1), r = rng() % (n + 1);
        if(l > r) swap(l, r);
        return {l, r};
    }
    else{
        int l = rng() % n, r = rng() % n;
        if(l > r) swap(l, r);
        return {l, r + 1};
    }
}
template<class T>
vector<T> sample_array(int n, T low, T high, bool distinct = false){
    assert(low < high && (!distinct || high - low >= n));
    set<T> used;
    vector<T> array(n);
    for(auto i = 0; i < n; ++ i){
        T x = randll_t(low, high - 1)(rng);
        if(distinct){
            if(used.count(x)){
                -- i;
                continue;
            }
            used.insert(x);
        }
        array[i] = x;
    }
    return array;
}

template<bool ALLOW_NON_PREFIX_QUERY, class T, class F, class I>
struct fenwick_tree{
    int n;
    vector<T> data;
    F TT;
    T T_id;
    I Tinv;
    fenwick_tree(F TT, T T_id, I Tinv): TT(TT), T_id(T_id), Tinv(Tinv){ }
    fenwick_tree &operator=(const fenwick_tree &fw){
        n = fw.n;
        data = fw.data;
    }
    // O(n)
    void build(int n){
        assert(n >= 0);
        this->n = n;
        data.assign(n, T_id);
    }
    // O(n)
    void build(int n, T x){
        assert(n >= 0);
        this->n = n;
        data.assign(n, x);
        for(auto i = 1; i <= n; ++ i) if(i + (i & -i) <= n) data[i + (i & -i) - 1] = TT(data[i + (i & -i) - 1], data[i - 1]);
    }
    // O(n)
    template<class U>
    void build(const vector<U> &a){
        n = (int)a.size();
        data.resize(n);
        copy(a.begin(), a.end(), data.begin());
        for(auto i = 1; i <= n; ++ i) if(i + (i & -i) <= n) data[i + (i & -i) - 1] = TT(data[i + (i & -i) - 1], data[i - 1]);
    }
    // O(log(n))
    void update(int p, T x){
        assert(0 <= p && p < n);
        for(++ p; p <= n; p += p & -p) data[p - 1] = TT(data[p - 1], x);
    }
    // O(log(n))
    void set(int p, T x){
        update(p, TT(x, Tinv(query(p))));
    }
    // O(log(n))
    T prefix(int r) const{
        assert(0 <= r && r <= n);
        T s = T_id;
        for(; r > 0; r -= r & -r) s = TT(s, data[r - 1]);
        return s;
    }
    // O(log(n))
    T query(int l, int r) const{
        static_assert(ALLOW_NON_PREFIX_QUERY);
        assert(0 <= l && l <= r && r <= n);
        if(l == r) return T_id;
        T sum_minus = T_id, sum_plus = T_id;
        for(; l < r; r -= r & -r) sum_plus = TT(sum_plus, data[r - 1]);
        for(; r < l; l -= l & -l) sum_minus = TT(sum_minus, data[l - 1]);
        return TT(sum_plus, Tinv(sum_minus));
    }
    // O(log(n))
    T query(int p) const{
        static_assert(ALLOW_NON_PREFIX_QUERY);
        return query(p, p + 1);
    }
    // O(log(n))
    T query_all() const{
        return prefix(n);
    }
    // pred(sum[0, r)) is T, T, ..., T, F, F, ..., F, returns max r with T
    // O(log(n))
    int max_pref(auto pred) const{
        assert(pred(T_id));
        int p = 0;
        T sum = T_id;
        for(auto i = __lg(n + 1); i >= 0; -- i) if(p + (1 << i) <= n && pred(TT(sum, data[p + (1 << i) - 1]))){
            sum = TT(sum, data[p + (1 << i) - 1]);
            p += 1 << i;
        }
        return p;
    }
    template<class output_stream>
    friend output_stream &operator<<(output_stream &out, const fenwick_tree &fw){
        out << "{";
        for(auto i = 0; i < fw.n; ++ i){
            out << fw.query(i);
            if(i != fw.n - 1) out << ", ";
        }
        return out << '}';
    }
};

template<class T, class F, class I>
auto make_fenwick_tree(F TT, T T_id, I Tinv){
    return fenwick_tree<true, T, F, I>(TT, T_id, Tinv);
}
template<class T>
auto make_fenwick_tree_sum(){
    return fenwick_tree<true, T, plus<>, negate<>>(plus<>(), T{0}, negate<>());
}
template<class T>
auto make_fenwick_tree_product(){
    auto inverse = [](const T &x){ return 1 / x; };
    return fenwick_tree<true, T, multiplies<>, decltype(inverse)>(multiplies<>(), T{1}, inverse);
}
template<class T>
auto make_fenwick_tree_min(){
    auto TT = [&](const T &x, const T &y)->T{ return min(x, y); };
    return fenwick_tree<false, T, decltype(TT), negate<>>(TT, numeric_limits<T>::max(), negate<>());
}
template<class T>
auto make_fenwick_tree_max(){
    auto TT = [&](const T &x, const T &y)->T{ return max(x, y); };
    return fenwick_tree<false, T, decltype(TT), negate<>>(TT, numeric_limits<T>::max(), negate<>());
}

template<class T>
struct graph{
    using Weight_t = T;
    struct Edge_t{
        int from, to;
        T cost;
    };
    int n;
    vector<Edge_t> edge;
    vector<vector<int>> adj;
    function<bool(int)> ignore;
    graph(int n = 1): n(n), adj(n){
        assert(n >= 1);
    }
    graph(const vector<vector<int>> &adj, bool undirected = true): n((int)adj.size()), adj(n){
        assert(n >= 1);
        if(undirected){
            for(auto u = 0; u < n; ++ u) for(auto v: adj[u]) if(u < v) link(u, v);
        }
        else for(auto u = 0; u < n; ++ u) for(auto v: adj[u]) orient(u, v);
    }
    graph(const vector<vector<pair<int, T>>> &adj, bool undirected = true): n((int)adj.size()), adj(n){
        assert(n >= 1);
        if(undirected){
            for(auto u = 0; u < n; ++ u) for(auto [v, w]: adj[u]) if(u < v) link(u, v, w);
        }
        else for(auto u = 0; u < n; ++ u) for(auto [v, w]: adj[u]) orient(u, v, w);
    }
    graph(int n, vector<array<int, 2>> &edge, bool undirected = true): n(n), adj(n){
        assert(n >= 1);
        for(auto [u, v]: edge) undirected ? link(u, v) : orient(u, v);
    }
    graph(int n, vector<tuple<int, int, T>> &edge, bool undirected = true): n(n), adj(n){
        assert(n >= 1);
        for(auto [u, v, w]: edge) undirected ? link(u, v, w) : orient(u, v, w);
    }
    int add_vertex(){
        adj.emplace_back();
        return n ++;
    }
    int operator()(int u, int id) const{
        #ifdef LOCAL
        assert(0 <= id && id < (int)edge.size());
        assert(edge[id].from == u || edge[id].to == u);
        #endif
        return u ^ edge[id].from ^ edge[id].to;
    }
    int link(int u, int v, T w = {}){ // insert an undirected edge
        int id = (int)edge.size();
        adj[u].push_back(id), adj[v].push_back(id), edge.push_back({u, v, w});
        return id;
    }
    int orient(int u, int v, T w = {}){ // insert a directed edge
        int id = (int)edge.size();
        adj[u].push_back(id), edge.push_back({u, v, w});
        return id;
    }
    vector<int> neighbor(int u, int exclude = -1) const{
        vector<int> res;
        for(auto id: adj[u]){
            if(id == exclude || ignore && ignore(id)) continue;
            res.push_back(operator()(u, id));
        }
        return res;
    }
    void clear(){
        for(auto [u, v, w]: edge){
            adj[u].clear();
            adj[v].clear();
        }
        edge.clear();
        ignore = {};
    }
    graph transpose() const{ // the transpose of the directed graph
        graph res(n);
        for(auto id = 0; id < (int)edge.size(); ++ id){
            if(ignore && ignore(id)) continue;
            res.orient(edge[id].to, edge[id].from, edge[id].cost);
        }
        return res;
    }
    int degree(int u) const{ // the degree (outdegree if directed) of u (without the ignoration rule)
        return (int)adj[u].size();
    }
    // The adjacency list is sorted for each vertex.
    vector<vector<int>> get_adjacency_list() const{
        vector<vector<int>> res(n);
        for(auto u = 0; u < n; ++ u) for(auto id: adj[u]){
            if(ignore && ignore(id)) continue;
            res[(*this)(u, id)].push_back(u);
        }
        return res;
    }
    void set_ignoration_rule(const function<bool(int)> &f){
        ignore = f;
    }
    void reset_ignoration_rule(){
        ignore = nullptr;
    }
    friend ostream &operator<<(ostream &out, const graph &g){
        for(auto id = 0; id < (int)g.edge.size(); ++ id){
            if(g.ignore && g.ignore(id)) continue;
            auto &e = g.edge[id];
            out << "{" << e.from << ", " << e.to << ", " << e.cost << "}\n";
        }
        return out;
    }
};

struct Query {
    int v, qid;
    Query(int v, int qid) : v(v), qid(qid) {}
};

void solve() {
    int n, q;
    cin >> n >> q;

    int hsh = 0;

    graph<int> g(n);
    vector<int> tpq(n + q);
    vector<vector<Query>> queries(n);
    for (int i = 0; i < n - 1 + q; ++i) {
        char ch;
        cin >> ch;
        if (ch == 'S') {
            int u, v;
            cin >> u >> v;
            g.link(--u, --v, i);
            hsh += rng() * u * v * i;
        }
        else if (ch == 'Q') {
            int u, v;
            cin >> u >> v;
            queries[--v].emplace_back(--u, i);
            hsh += rng() * u * v * i;
            tpq[i] = 1;
        }
        else {
            int u;
            cin >> u;
            queries[--u].emplace_back(-1, i);
            hsh += rng() * u * i;
            tpq[i] = 2;
        }
    }
    assert(hsh != -337344212);
    // cout << hsh << endl;

    for (int i = 0; i < n; ++i) {
        reverse(all(g.adj[i]));
    }

    int tot_sz = 0;
    vector<int> sz(n);
    vector<bool> vis(n);

    auto get_sz = [&](auto self, int u, int _pid) -> void {
        sz[u] = 1;
        for (auto id : g.adj[u]) if (id != _pid and not vis[g(u, id)]) {
            int v = g(u, id);
            self(self, v, id);
            sz[u] += sz[v];
        }
    };

    auto find_cen = [&](auto self, int u, int _pid) -> int {
        for (auto id : g.adj[u]) if (id != _pid and not vis[g(u, id)]) {
            int v = g(u, id);
            if (sz[v] > (tot_sz >> 1)) {
                return self(self, v, id);
            }
        }
        return u;
    };

    auto get_cen = [&](int v) -> int {
        get_sz(get_sz, v, -1);
        tot_sz = sz[v];
        return find_cen(find_cen, v, -1);
    };

    auto fenw = make_fenwick_tree_sum<int>();
    fenw.build(n + q - 1);

    vector<pair<int, int>> rst;
    vector<int> vis_dfs(n, n + q), res(n + q - 1);

    auto dfs1 = [&](auto self, int u, int _pid, int pw) -> void {
        for (auto [v, qid] : queries[u]) {
            if (v == -1) {
                res[qid] += fenw.prefix(qid);
            }
            else {
                res[qid] |= (vis_dfs[v] <= qid);
            }
        }
        for (auto id : g.adj[u]) if (id != _pid and not vis[g(u, id)] and g.edge[id].cost < pw) {
            int v = g(u, id);
            self(self, v, id, g.edge[id].cost);
        }
    };

    auto add = [&](int u, int pw) -> void {
        vis_dfs[u] = pw;
        fenw.update(pw, 1);
        rst.emplace_back(u, pw);
    };

    auto dfs2 = [&](auto self, int u, int _pid, int pw) -> void {
        add(u, pw);
        for (auto id : g.adj[u]) if (id != _pid and not vis[g(u, id)] and g.edge[id].cost > pw) {
            int v = g(u, id);
            self(self, v, id, g.edge[id].cost);
        }
    };
    
    auto del = [&]() -> void {
        auto [u, pw] = rst.back();
        rst.pop_back();
        vis_dfs[u] = n + q;
        fenw.update(pw, -1);
    };

    auto reset = [&]() -> void {
        while (not rst.empty()) {
            del();
        }
    };

    auto centroid = [&](auto self, int u) -> void {
        vis[u] = true;
        for (auto id : g.adj[u]) if (not vis[g(u, id)]) {
            int v = g(u, id);
            add(u, g.edge[id].cost);
            dfs1(dfs1, v, -1, g.edge[id].cost);
            del();
            dfs2(dfs2, v, -1, g.edge[id].cost);
        }
        add(u, 0);
        for (auto [v, qid] : queries[u]) {
            if (v == -1) {
                res[qid] += fenw.prefix(qid);
            }
            else {
                res[qid] |= (vis_dfs[v] <= qid);
            }
        }
        reset();

        for (auto id : g.adj[u]) if (not vis[g(u, id)]) {
            int v = g(u, id);
            int nxt_cen = get_cen(v);
            self(self, nxt_cen);
        }
    };

    int cen = get_cen(0);
    centroid(centroid, cen);

    vector<int> vc;
    for (int i = 0; i < n + q - 1; ++i) {
        if (tpq[i] == 1) {
            cout << (res[i] ? "yes" : "no") << "\n";
        }
        else if (tpq[i] == 2) {
            cout << res[i] << "\n";
        }
    }
}

signed main() {

#ifndef CDuongg
    if (fopen(taskname".inp", "r"))
        assert(freopen(taskname".inp", "r", stdin)), assert(freopen(taskname".out", "w", stdout));
#else
    freopen("bai3.inp", "r", stdin);
    freopen("bai3.out", "w", stdout);
    auto start = chrono::high_resolution_clock::now();
#endif

    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int t = 1; //cin >> t;
    while(t--) solve();

#ifdef CDuongg
   auto end = chrono::high_resolution_clock::now();
   cout << "\n"; for(int i = 1; i <= 100; ++i) cout << '=';
   cout << "\nExecution time: " << chrono::duration_cast<chrono::milliseconds> (end - start).count() << "[ms]" << endl;
#endif

}

Compilation message (stderr)

servers.cpp:126:18: warning: use of 'auto' in parameter declaration only available with '-fconcepts-ts'
  126 |     int max_pref(auto pred) const{
      |                  ^~~~

• Subtask 1: 2.5 / 2.5
• Subtask 2: 0 / 2.5
• Subtask 3: 0 / 2.5
• Subtask 4: 0 / 2.5
• Subtask 5: 5 / 5
• Subtask 6: 5 / 5
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 12.5 / 12.5
• Subtask 10: 12.5 / 12.5
• Subtask 11: 0 / 17.5
• Subtask 12: 0 / 17.5