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Submission #619943

# Submission time Handle Problem Language Result Execution time Memory
619943 2022-08-02T17:28:19 Z chuangsheep timeismoney (balkan11_timeismoney) C++11
95 / 100
 475 ms 852 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long int;
using pii = pair<ll, ll>;
using Edge = array<ll, 5>;

struct DSU
{
  vector<ll> g;
  DSU(ll n) : g(n, -1) {}
  ll find(ll a)
  {
    if (g[a] < 0)
      return a;
    else
      return g[a] = find(g[a]);
  }
  bool unite(ll a, ll b)
  {
    a = find(a);
    b = find(b);
    if (a == b)
      return false;
    if (g[a] > g[b])
      swap(a, b);
    g[a] += g[b];
    g[b] = a;
    return true;
  }
};

pair<pii, vector<ll>> kruskal(ll n, vector<Edge> &edges, vector<ll> &weights)
{
  sort(begin(edges), end(edges), [&](const Edge &e1, const Edge &e2)
       { return weights[e1[4]] < weights[e2[4]]; });
  DSU dsu(n);
  vector<ll> mst;
  ll t = 0;
  ll c = 0;
  for (Edge &e : edges)
  {
    if (dsu.unite(e[0], e[1]))
    {
      t += e[2];
      c += e[3];
      mst.push_back(e[4]);
    }
  }
  return {{t, c}, mst};
}

ll cross(pii A, pii B, pii C)
{
  pii AB = {B.first - A.first, B.second - A.second};
  pii AC = {C.first - A.first, C.second - A.second};
  return AB.first * AC.second - AB.second * AC.first;
}

int main()
{
#if defined(DEBUG) && !defined(ONLINE_JUDGE)
  // DEBUG
  cerr << "DEBUG flag set - see test.out for output\n";
  freopen("/home/chuang/shared-drives/G:/repos/cp/ois/boi11/timeismoney/test.in", "r", stdin);
  freopen("/home/chuang/shared-drives/G:/repos/cp/ois/boi11/timeismoney/test.out", "w", stdout);
#else
  cin.tie(0)->sync_with_stdio(false);
#endif

  ll N, M;
  cin >> N >> M;

  vector<Edge> edges(M);
  for (ll i = 0; i < M; i++)
  {
    ll x, y, t, c;
    cin >> x >> y >> t >> c;
    edges[i] = {x, y, t, c, i};
  }

  vector<ll> best_MST;
  pii best_V = {1e8, 1e8};

  vector<ll> weights(M);
  for (ll i = 0; i < M; i++)
  {
    weights[edges[i][4]] = edges[i][2];
  }
  pii A;
  tie(A, best_MST) = kruskal(N, edges, weights);
  best_V = A;
  for (ll i = 0; i < M; i++)
  {
    weights[edges[i][4]] = edges[i][3];
  }
  pii B = kruskal(N, edges, weights).first;

  stack<pair<pii, pii>> to_search;
  to_search.push({A, B});

  while (!to_search.empty())
  {
    tie(A, B) = to_search.top();
    to_search.pop();

    for (ll i = 0; i < M; i++)
    {
      weights[edges[i][4]] = edges[i][3] * (B.first - A.first) -
                             edges[i][2] * (B.second - A.second);
    }
    pii C;
    vector<ll> current_MST;
    tie(C, current_MST) = kruskal(N, edges, weights);

    if (cross(A, B, C) >= 0)
      continue;

    if ((ll)C.first * C.second < (ll)best_V.first * best_V.second)
    {
      best_V = C;
      best_MST = current_MST;
    }

    to_search.push({A, C});
    to_search.push({C, B});
  }

  cout << best_V.first << " " << best_V.second << "\n";
  sort(begin(edges), end(edges), [](const Edge &e1, const Edge &e2)
       { return e1[4] < e2[4]; });
  for (ll &id : best_MST)
  {
    cout << edges[id][0] << " " << edges[id][1] << "\n";
  }
}

Subtask #1
95.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 316 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 324 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 2 ms 424 KB Output is correct
8 Correct 6 ms 852 KB Output is correct
9 Correct 1 ms 320 KB Output is correct
10 Incorrect 1 ms 212 KB Output isn't correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 4 ms 340 KB Output is correct
15 Correct 2 ms 324 KB Output is correct
16 Correct 52 ms 428 KB Output is correct
17 Correct 52 ms 340 KB Output is correct
18 Correct 50 ms 460 KB Output is correct
19 Correct 449 ms 852 KB Output is correct
20 Correct 475 ms 852 KB Output is correct