結果
| 問題 |
No.3206 う し た ウ ニ 木 あ く ん 笑
|
| ユーザー |
 hitonanode
|
| 提出日時 | 2025-07-18 21:29:51 |
| 言語 | C++23 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 253 ms / 3,000 ms |
| コード長 | 11,005 bytes |
| コンパイル時間 | 3,027 ms |
| コンパイル使用メモリ | 240,864 KB |
| 実行使用メモリ | 32,212 KB |
| 最終ジャッジ日時 | 2025-07-18 21:30:15 |
| 合計ジャッジ時間 | 6,861 ms |
|
ジャッジサーバーID （参考情報） |
judge1 / judge3 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 2 |
| other | AC * 30 |
ソースコード
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <deque>
#include <forward_list>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <optional>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using lint = long long;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_;
#define ALL(x) (x).begin(), (x).end()
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template <typename T> bool chmax(T &m, const T q) { return m < q ? (m = q, true) : false; }
template <typename T> bool chmin(T &m, const T q) { return m > q ? (m = q, true) : false; }
const std::vector<std::pair<int, int>> grid_dxs{{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
int floor_lg(long long x) { return x <= 0 ? -1 : 63 - __builtin_clzll(x); }
template <class T1, class T2> T1 floor_div(T1 num, T2 den) { return (num > 0 ? num / den : -((-num + den - 1) / den)); }
template <class T1, class T2> std::pair<T1, T2> operator+(const std::pair<T1, T2> &l, const std::pair<T1, T2> &r) { return std::make_pair(l.first + r.first, l.second + r.second); }
template <class T1, class T2> std::pair<T1, T2> operator-(const std::pair<T1, T2> &l, const std::pair<T1, T2> &r) { return std::make_pair(l.first - r.first, l.second - r.second); }
template <class T> std::vector<T> sort_unique(std::vector<T> vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end()); return vec; }
template <class T> int arglb(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::lower_bound(v.begin(), v.end(), x)); }
template <class T> int argub(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::upper_bound(v.begin(), v.end(), x)); }
template <class IStream, class T> IStream &operator>>(IStream &is, std::vector<T> &vec) { for (auto &v : vec) is >> v; return is; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::vector<T> &vec);
template <class OStream, class T, size_t sz> OStream &operator<<(OStream &os, const std::array<T, sz> &arr);
template <class OStream, class T, class TH> OStream &operator<<(OStream &os, const std::unordered_set<T, TH> &vec);
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const pair<T, U> &pa);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::deque<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::set<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::multiset<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::unordered_multiset<T> &vec);
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const std::pair<T, U> &pa);
template <class OStream, class TK, class TV> OStream &operator<<(OStream &os, const std::map<TK, TV> &mp);
template <class OStream, class TK, class TV, class TH> OStream &operator<<(OStream &os, const std::unordered_map<TK, TV, TH> &mp);
template <class OStream, class... T> OStream &operator<<(OStream &os, const std::tuple<T...> &tpl);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::vector<T> &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <class OStream, class T, size_t sz> OStream &operator<<(OStream &os, const std::array<T, sz> &arr) { os << '['; for (auto v : arr) os << v << ','; os << ']'; return os; }
template <class... T> std::istream &operator>>(std::istream &is, std::tuple<T...> &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); return is; }
template <class OStream, class... T> OStream &operator<<(OStream &os, const std::tuple<T...> &tpl) { os << '('; std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os << ')'; }
template <class OStream, class T, class TH> OStream &operator<<(OStream &os, const std::unordered_set<T, TH> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const std::pair<T, U> &pa) { return os << '(' << pa.first << ',' << pa.second << ')'; }
template <class OStream, class TK, class TV> OStream &operator<<(OStream &os, const std::map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
template <class OStream, class TK, class TV, class TH> OStream &operator<<(OStream &os, const std::unordered_map<TK, TV, TH> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
#ifdef HITONANODE_LOCAL
const string COLOR_RESET = "\033[0m", BRIGHT_GREEN = "\033[1;32m", BRIGHT_RED = "\033[1;31m", BRIGHT_CYAN = "\033[1;36m", NORMAL_CROSSED = "\033[0;9;37m", RED_BACKGROUND = "\033[1;41m", NORMAL_FAINT = "\033[0;2m";
#define dbg(x) std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << std::endl
#define dbgif(cond, x) ((cond) ? std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << std::endl : std::cerr)
#else
#define dbg(x) ((void)0)
#define dbgif(cond, x) ((void)0)
#endif
#include <cassert>
#include <cstdlib>
#include <utility>
#include <vector>
// Rerooting
// Reference:
// - https://atcoder.jp/contests/abc222/editorial/2749
// - https://null-mn.hatenablog.com/entry/2020/04/14/124151
template <class Edge, class Subtree, class Children, Children (*rake)(Children, Children),
Children (*add_edge)(Subtree, int, Edge), Subtree (*add_vertex)(Children, int),
Children (*e)()>
struct rerooting {
int n_;
std::vector<int> par, visited;
std::vector<std::vector<std::pair<int, Edge>>> to;
// dp_subtree[i] = DP(root=i, edge (i, par[i]) is removed).
std::vector<Subtree> dp_subtree;
// dp_par[i] = DP(root=par[i], edge (i, par[i]) is removed). dp_par[root] is meaningless.
std::vector<Subtree> dp_par;
// dpall[i] = DP(root=i, all edges exist).
std::vector<Subtree> dpall;
rerooting(const std::vector<std::vector<std::pair<int, Edge>>> &to_)
: n_(to_.size()), par(n_, -1), visited(n_, 0), to(to_) {
for (int i = 0; i < n_; ++i) dp_subtree.push_back(add_vertex(e(), i));
dp_par = dpall = dp_subtree;
}
void run_connected(int root) {
if (visited.at(root)) return;
visited.at(root) = 1;
std::vector<int> visorder{root};
for (int t = 0; t < int(visorder.size()); ++t) {
int now = visorder.at(t);
for (const auto &[nxt, _] : to[now]) {
if (visited.at(nxt)) continue;
visorder.push_back(nxt);
visited.at(nxt) = 1;
par.at(nxt) = now;
}
}
for (int t = int(visorder.size()) - 1; t >= 0; --t) {
const int now = visorder.at(t);
Children ch = e();
for (const auto &[nxt, edge] : to.at(now)) {
if (nxt != par.at(now)) ch = rake(ch, add_edge(dp_subtree.at(nxt), nxt, edge));
}
dp_subtree.at(now) = add_vertex(ch, now);
}
std::vector<Children> left;
for (int now : visorder) {
const int m = to.at(now).size();
left.assign(m + 1, e());
for (int j = 0; j < m; j++) {
const auto &[nxt, edge] = to.at(now).at(j);
const Subtree &st = (nxt == par.at(now) ? dp_par.at(now) : dp_subtree.at(nxt));
left.at(j + 1) = rake(left.at(j), add_edge(st, nxt, edge));
}
dpall.at(now) = add_vertex(left.back(), now);
Children rprod = e();
for (int j = m - 1; j >= 0; --j) {
const auto &[nxt, edge] = to.at(now).at(j);
if (nxt != par.at(now)) dp_par.at(nxt) = add_vertex(rake(left.at(j), rprod), now);
const Subtree &st = (nxt == par.at(now) ? dp_par.at(now) : dp_subtree.at(nxt));
rprod = rake(add_edge(st, nxt, edge), rprod);
}
}
}
void run() {
for (int i = 0; i < n_; ++i) {
if (!visited.at(i)) run_connected(i);
}
}
const Subtree &get_subtree(int root_, int par_) const {
if (par_ < 0) return dpall.at(root_);
if (par.at(root_) == par_) return dp_subtree.at(root_);
if (par.at(par_) == root_) return dp_par.at(par_);
std::exit(1);
}
};
/* Template:
struct Subtree {};
struct Children {};
struct Edge {};
vector<vector<pair<int, Edge>>> to;
rerooting<Edge, Subtree, Children, rake, add_edge, add_vertex, e> tree(to);
*/
using Subtree = int;
using Children = int;
using Edge = int;
Children e() { return 0; }
Children rake(Children x, Children y) { return max(x, y); }
Children add_edge(Subtree x, int ch_id, Edge edge) { return x; }
Subtree add_vertex(Children x, int v_id) { return x + 1; }
int main() {
int N;
cin >> N;
vector<vector<pair<int, Edge>>> to(N);
REP(e, N - 1) {
int u, v;
cin >> u >> v;
--u, --v;
to.at(u).emplace_back(v, e);
to.at(v).emplace_back(u, e);
}
rerooting<Edge, Subtree, Children, rake, add_edge, add_vertex, e> tree(to);
tree.run();
dbg(tree.dpall);
int ret = 1;
REP(i, N) {
vector<int> vs;
for (auto [adj, _] : to.at(i)) {
vs.push_back(tree.get_subtree(adj, i));
}
sort(vs.rbegin(), vs.rend());
dbg(vs);
REP(t, vs.size()) chmax(ret, vs.at(t) * (t + 1) + 1);
}
cout << ret << '\n';
}