結果

問題 No.1639 最小通信路
ユーザー stoq
提出日時 2021-08-06 21:53:51
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 15 ms / 2,000 ms
コード長 4,443 bytes
コンパイル時間 9,873 ms
コンパイル使用メモリ 546,540 KB
最終ジャッジ日時 2025-01-23 15:12:05
ジャッジサーバーID
（参考情報） 		judge2 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 43
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 # 

#define MOD_TYPE 1

#pragma region Macros

#include <bits/stdc++.h>
using namespace std;

#if 1
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#endif

#if 0
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/tag_and_trait.hpp>
#include <ext/rope>
using namespace __gnu_pbds;
using namespace __gnu_cxx;
template <typename T>
using extset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#endif

#if 1
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/multiprecision/cpp_dec_float.hpp>
using Int = boost::multiprecision::cpp_int;
using lld = boost::multiprecision::cpp_dec_float_100;
#endif

using ll = long long int;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pld = pair<ld, ld>;
template <typename T>
using smaller_queue = priority_queue<T, vector<T>, greater<T>>;

constexpr ll MOD = (MOD_TYPE == 1 ? (ll)(1e9 + 7) : 998244353);
constexpr int INF = (int)1e9 + 10;
constexpr ll LINF = (ll)4e18;
constexpr ld PI = acos(-1.0);
constexpr ld EPS = 1e-7;
constexpr int Dx[] = {0, 0, -1, 1, -1, 1, -1, 1, 0};
constexpr int Dy[] = {1, -1, 0, 0, -1, -1, 1, 1, 0};

#define REP(i, m, n) for (ll i = m; i < (ll)(n); ++i)
#define rep(i, n) REP(i, 0, n)
#define REPI(i, m, n) for (int i = m; i < (int)(n); ++i)
#define repi(i, n) REPI(i, 0, n)
#define MP make_pair
#define MT make_tuple
#define YES(n) cout << ((n) ? "YES" : "NO") << "\n"
#define Yes(n) cout << ((n) ? "Yes" : "No") << "\n"
#define possible(n) cout << ((n) ? "possible" : "impossible") << "\n"
#define Possible(n) cout << ((n) ? "Possible" : "Impossible") << "\n"
#define all(v) v.begin(), v.end()
#define NP(v) next_permutation(all(v))
#define dbg(x) cerr << #x << ":" << x << "\n";

struct io_init
{
  io_init()
  {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << setprecision(30) << setiosflags(ios::fixed);
  };
} io_init;
template <typename T>
inline bool chmin(T &a, T b)
{
  if (a > b)
  {
    a = b;
    return true;
  }
  return false;
}
template <typename T>
inline bool chmax(T &a, T b)
{
  if (a < b)
  {
    a = b;
    return true;
  }
  return false;
}
inline ll CEIL(ll a, ll b)
{
  return (a + b - 1) / b;
}
template <typename A, size_t N, typename T>
inline void Fill(A (&array)[N], const T &val)
{
  fill((T *)array, (T *)(array + N), val);
}
template <typename T, typename U>
constexpr istream &operator>>(istream &is, pair<T, U> &p) noexcept
{
  is >> p.first >> p.second;
  return is;
}
template <typename T, typename U>
constexpr ostream &operator<<(ostream &os, pair<T, U> &p) noexcept
{
  os << p.first << " " << p.second;
  return os;
}
#pragma endregion

random_device seed_gen;
mt19937_64 engine(seed_gen());

// --------------------------------------

struct UnionFind
{
  vector<int> par, rank_;

  UnionFind() {}
  UnionFind(int n) : par(n), rank_(n, 0) { iota(begin(par), end(par), 0); }

  int root(int x) { return par[x] == x ? x : par[x] = root(par[x]); }

  bool same(int x, int y) { return root(x) == root(y); }

  void unite(int x, int y)
  {
    x = root(x);
    y = root(y);
    if (x == y)
      return;

    if (rank_[x] < rank_[y])
    {
      par[x] = y;
    }
    else
    {
      par[y] = x;
      if (rank_[x] == rank_[y])
        rank_[x]++;
    }
  }
};

template <typename T>
struct kruskal
{
  UnionFind uf;
  kruskal(int n = 200010) : uf(n) {}

  struct edge
  {
    int u, v;
    T cost;
    int num;
  };

  vector<edge> E;
  set<int> used_num;
  void add_E(int s, int t, T w, int i) { E.push_back({s, t, w, i}); }

  T calc()
  {
    sort(E.begin(), E.end(), [](edge &e1, edge &e2)
         { return e1.cost < e2.cost; });
    T res = 0;
    for (auto e : E)
    {
      if (!uf.same(e.u, e.v))
      {
        uf.unite(e.u, e.v);
        res += e.cost;
        used_num.insert(e.num);
      }
    }
    return res;
  }

  bool used(int i) { return used_num.count(i); }
};

void solve()
{
  int n;
  cin >> n;
  int m = n * (n - 1) / 2;
  tuple<Int, int, int, int> v[100 * 50];
  kruskal<int> ks(n);
  repi(i, m)
  {
    int a, b;
    Int c;
    cin >> a >> b >> c;
    a--, b--;
    v[i] = {c, a, b, i};
  }
  sort(v, v + m);
  rep(j, m)
  {
    auto [c, a, b, i] = v[j];
    ks.add_E(a, b, j, i);
  }
  ks.calc();
  Int ans = 0;
  for (auto i : ks.used_num)
  {
    chmax(ans, get<0>(v[i]));
  }
  cout << ans << "\n";
}

int main()
{
  solve();
}
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