結果

問題 No.3206 う　し　た　ウ　ニ　木　あ　く　ん　笑
コンテスト
ユーザー 横山緑
提出日時 2025-07-19 13:36:38
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 714 ms / 3,000 ms
コード長 8,551 bytes
コンパイル時間 3,835 ms
コンパイル使用メモリ 305,744 KB
実行使用メモリ 220,276 KB
最終ジャッジ日時 2025-07-19 13:36:53
合計ジャッジ時間 13,937 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge4
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
sample AC * 2
other AC * 30
権限があれば一括ダウンロードができます

ソースコード

diff # 

#line 2 "template.hpp"
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <debug.hpp>
#else
template <class T>
concept Streamable = requires(ostream os, T &x) { os << x; };
template <class mint>
concept is_modint = requires(mint &x) {
    { x.val() } -> std::convertible_to<int>;
};
#define debug(...)
#endif
template <Streamable T> void print_one(const T &value) { cout << value; }
template <is_modint T> void print_one(const T &value) { cout << value.val(); }
void print() { cout << '\n'; }
template <class T, class... Ts> void print(const T &a, const Ts &...b) {
    print_one(a);
    ((cout << ' ', print_one(b)), ...);
    cout << '\n';
}
template <ranges::range Iterable>
    requires(!Streamable<Iterable>)
void print(const Iterable &v) {
    for(auto it = v.begin(); it != v.end(); ++it) {
        if(it != v.begin())
            cout << " ";
        print_one(*it);
    }
    cout << '\n';
}
using vi = vector<int>;
using vii = vector<vector<int>>;
using pii = pair<int, int>;
using ll = long long;
using vl = vector<ll>;
using vll = vector<vl>;
using pll = pair<ll, ll>;
#define all(v) begin(v), end(v)
template <class T> void UNIQUE(T &v) {
    ranges::sort(v);
    v.erase(unique(all(v)), end(v));
}
template <typename T> inline bool chmax(T &a, T b) {
    return ((a < b) ? (a = b, true) : (false));
}
template <typename T> inline bool chmin(T &a, T b) {
    return ((a > b) ? (a = b, true) : (false));
}
// https://trap.jp/post/1224/
template <class... T> constexpr auto min(T... a) {
    return min(initializer_list<common_type_t<T...>>{a...});
}
template <class... T> constexpr auto max(T... a) {
    return max(initializer_list<common_type_t<T...>>{a...});
}
template <class... T> void input(T &...a) { (cin >> ... >> a); }
template <class T> void input(vector<T> &a) {
    for(T &x : a)
        cin >> x;
}
#define INT(...)                                                               \
    int __VA_ARGS__;                                                           \
    input(__VA_ARGS__)
#define LL(...)                                                                \
    long long __VA_ARGS__;                                                     \
    input(__VA_ARGS__)
#define STR(...)                                                               \
    string __VA_ARGS__;                                                        \
    input(__VA_ARGS__)
#define REP1_0(n, c) REP1_1(n, c)
#define REP1_1(n, c)                                                           \
    for(ll REP_COUNTER_##c = 0; REP_COUNTER_##c < (ll)(n); REP_COUNTER_##c++)
#define REP1(n) REP1_0(n, __COUNTER__)
#define REP2(i, a) for(ll i = 0; i < (ll)(a); i++)
#define REP3(i, a, b) for(ll i = (ll)(a); i < (ll)(b); i++)
#define REP4(i, a, b, c) for(ll i = (ll)(a); i < (ll)(b); i += (ll)(c))
#define overload4(a, b, c, d, e, ...) e
#define rep(...) overload4(__VA_ARGS__, REP4, REP3, REP2, REP1)(__VA_ARGS__)
ll inf = 3e18;
vl dx = {1, -1, 0, 0};
vl dy = {0, 0, 1, -1};
template <class T> constexpr T floor(T x, T y) noexcept {
    return x / y - ((x ^ y) < 0 and x % y);
}
template <class T> constexpr T ceil(T x, T y) noexcept {
    return x / y + ((x ^ y) >= 0 and x % y);
}
// yの符号に関わらず非負で定義 \bmod:texコマンド
template <class T> constexpr T bmod(T x, T y) noexcept {
    T m = x % y;
    return (m < 0) ? m + (y > 0 ? y : -y) : m;
}
template <std::signed_integral T> constexpr int bit_width(T x) noexcept {
    return std::bit_width((uint64_t)x);
}
template <std::signed_integral T> constexpr int popcount(T x) noexcept {
    return std::popcount((uint64_t)x);
}
constexpr bool kth_bit(auto n, auto k) { return (n >> k) & 1; }
#line 3 "graph/graph-template.hpp"
/**
 * @brief Graph Template(グラフテンプレート)
 * @see https://ei1333.github.io/library/graph/graph-template.hpp
 */
template <class T = ll> struct Edge {
    int from, to;
    T cost;
    int idx;
    Edge() = default;
    Edge(int from, int to, T cost = 1, int idx = -1)
        : from(from), to(to), cost(cost), idx(idx) {}
    Edge &operator=(const int &x) {
        to = x;
        return *this;
    }
    operator int() const { return to; }
};
template <class T = ll> struct Graph {
    using cost_type = T;
    vector<vector<Edge<T>>> g;
    int es; // edge_size
    Graph() = default;
    explicit Graph(int n) : g(n), es(0) {};
    int size() const { return ssize(g); }
    void add_directed_edge(int from, int to, T cost = 1) {
        g[from].emplace_back(from, to, cost, es++);
    }
    void add_edge(int from, int to, T cost = 1) {
        g[from].emplace_back(from, to, cost, es);
        g[to].emplace_back(to, from, cost, es++);
    }
    vector<Edge<T>> &operator[](const int &k) { return g[k]; }
    const vector<Edge<T>> &operator[](const int &k) const { return g[k]; }
    void read(int m, int padding = -1, bool weighted = false,
              bool directed = false) {
        for(int i = 0; i < m; ++i) {
            int a, b;
            T c(1);
            cin >> a >> b;
            a += padding;
            b += padding;
            if(weighted)
                cin >> c;
            if(directed)
                add_directed_edge(a, b, c);
            else
                add_edge(a, b, c);
        }
    }
};
#line 3 "tree/rerooting.hpp"
/*
    今の実装では0を根としたときに葉に向かう辺しか見ていない
    辺の向きによってcostを変えるような場合には対応していない
    apply関数、idxもほしいしEdge<Cost>を引数にする？
    でも↑の事情からfrom,toが入れ替わっている可能性がある
*/
// https://atcoder.jp/contests/abc222/editorial/2749
// https://nyaannyaan.github.io/library/tree/rerooting.hpp
// TreeType : Graph<Cost>
// MergeFunc : Data(Data,Data)
// ApplyFunc : Data(Data,int from,int to,Cost)
/*
using Data = ;
using Cost = ;
Graph<Cost> g;
Data leaf = ;
auto merge = [](Data a, Data b) {};
auto apply = [](Data data, int from, int to, Cost cost) {};
Rerooting<Data, decltype(g), decltype(merge), decltype(apply)> dp(
    g, merge, apply, leaf);
*/
template <class Data, class TreeType, class MergeFunc, class ApplyFunc>
struct Rerooting {
    const TreeType &g;
    const MergeFunc merge;
    const ApplyFunc apply;
    const Data leaf;
    vector<Data> dp, memo;
    Rerooting(const TreeType &g, MergeFunc merge, ApplyFunc apply, Data leaf)
        : g(g), merge(merge), apply(apply), leaf(leaf), dp(g.size(), leaf),
          memo(g.size(), leaf) {
        dfs1(0, -1);
        dfs2(0, -1, leaf);
    }
    const Data &operator[](int i) const { return dp[i]; }

    void dfs1(int cur, int p) {
        for(auto &d : g[cur]) {
            if(d.to == p)
                continue;
            dfs1(d.to, cur);
            memo[cur] = merge(memo[cur], apply(memo[d.to], d.to, cur, d.cost));
        }
    }
    void dfs2(int cur, int p, const Data &val) {
        vector<Data> ds{val};
        for(auto &d : g[cur]) {
            if(d.to == p)
                continue;
            ds.emplace_back(apply(memo[d.to], d.to, cur, d.cost));
        }
        vector<Data> left(ds.size() + 1, leaf), right(ds.size() + 1, leaf);
        for(int i = 0; i + 1 < (int)left.size(); i++)
            left[i + 1] = merge(left[i], ds[i]);
        for(int i = ssize(right) - 2; 0 < i; i--)
            right[i] = merge(right[i + 1], ds[i]);
        dp[cur] = left.back();
        int idx = 1;
        for(auto &d : g[cur]) {
            if(d.to == p)
                continue;
            Data tmp = merge(left[idx], right[idx + 1]);
            tmp = apply(tmp, cur, d.to, d.cost);
            dfs2(d.to, cur, tmp);
            idx++;
        }
    }
};
#line 4 "/home/y_midori/cp/a.cpp"
int main() {
    using Data = vi;
    using Cost = int;
    INT(n);
    Graph<Cost> g(n);
    g.read(n - 1);
    Data leaf = {0};
    auto merge = [](Data a, Data b) {
        if(b.size() > a.size())
            swap(a, b);
        if(b.empty())
            return a;
        a.insert(end(a), begin(b), end(b));
        return a;
    };
    auto apply = [](Data data, int from, int to, Cost cost) {
        return Data({ranges::max(data) + 1});
    };
    Rerooting<Data, decltype(g), decltype(merge), decltype(apply)> dp(
        g, merge, apply, leaf);
    int ans = 0;
    for(auto &vi : dp.dp) {
        ranges::sort(vi, greater());
        rep(i, ssize(vi)) { chmax<int>(ans, 1 + (i + 1) * vi[i]); }
    }
    print(ans);
}
0