Submission #842345

#	Time	Username	Problem	Language	Result	Execution time	Memory
842345		flashmt	Closing Time (IOI23_closing)	C++17	43 / 100	107 ms	23344 KiB

closing

#include "closing.h"
#ifdef LOCAL
#include "Debug.h"
#else
#define debug(...) 42
#endif
#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
const long long oo = 1LL << 62;

int n;
vector<pair<int, int>> a[N];

vector<long long> bfs(int s)
{
  vector<long long> dist(n, -1);
  queue<int> q;
  dist[s] = 0;
  q.push(s);
  while (!empty(q))
  {
    int x = q.front();
    q.pop();
    for (auto [y, w] : a[x])
      if (dist[y] < 0)
      {
        dist[y] = dist[x] + w;
        q.push(y);
      }
  }
  return dist;
}

int isLinear()
{
  for (int i = 0; i + 1 < n; i++)
  {
    int isGood = 0;
    for (auto [j, _] : a[i])
      if (j == i + 1)
        isGood = 1;
    if (!isGood)
      return 0;
  }
  return 1;
}

int max_score(int N, int A, int B, long long budget, vector<int> U, vector<int> V, vector<int> W)
{
  n = N;
  for (int i = 0; i < n; i++)
    a[i].clear();
  for (int i = 0; i < size(U); i++)
  {
    a[U[i]].push_back({V[i], W[i]});
    a[V[i]].push_back({U[i], W[i]});
  }

  auto distA = bfs(A);
  auto distB = bfs(B);
  auto distAB = distA[B];

  if (distAB > budget * 2)
  {
    vector<long long> allDists = distA;
    for (auto d : distB)
      allDists.push_back(d);
    sort(begin(allDists), end(allDists));
    int ans = 0;
    for (auto d : allDists)
      if (d <= budget)
      {
        ans++;
        budget -= d;
      }
    return ans;
  }

  if (isLinear())
  {
    vector<long long> sumA(n), sumB(n), sumAB(n);
    for (int i = A; i <= B; i++)
    {
      sumA[i] = distA[i];
      sumAB[i] = max(distA[i], distB[i]);
      if (i)
      {
        sumA[i] += sumA[i - 1];
        sumAB[i] += sumAB[i - 1];
      }
    }
    for (int i = B - 1; i >= A; i--)
      sumB[i] = sumB[i + 1] + distB[i];

    vector<pair<long long, int>> ext;
    for (int i = 0; i < n; i++)
      if (i < A) ext.push_back({distA[i], i});
      else if (i > B) ext.push_back({distB[i], i});

    vector<long long> costFor(n, oo);
    costFor[0] = 0;
    sort(begin(ext), end(ext));
    for (int i = 0; i < size(ext); i++)
      costFor[i + 1] = costFor[i] + ext[i].first;

    int ans = 0;
    for (int l = A; l <= B; l++)
      for (int r = A; r <= B; r++)
      {
        long long cost = 0;
        int curAns = l - A + 1 + B - r + 1;
        if (l < r) cost = sumA[l] + sumB[r];
        else
        {
          cost = sumAB[l];
          if (r)
          {
            cost -= sumAB[r - 1];
            cost += sumA[r - 1];
          }
          if (l + 1 < n)
            cost += sumB[l + 1];
        }

        if (cost > budget)
          continue;

        if (l < B && r > A)
        {
          int u = upper_bound(begin(costFor), end(costFor), budget - cost) - begin(costFor);
          curAns += u - 1;
        }
        else
        {
          long long rem = budget - cost;
          int both = 0;
          for (int i = 0; i < size(ext); i++)
          {
            auto [extCost, id] = ext[i];
            while (both && extCost > distAB)
            {
              rem -= distAB;
              if (rem < 0)
                break;
              curAns++;
              both--;
            }

            rem -= extCost;
            if (rem < 0)
              break;
            curAns++;
            if (id < A && r == A) both++;
            else if (id > B && l == B) both++;
          }

          if (rem >= 0)
            curAns += min(1LL * both, rem / distAB);
        }

        ans = max(ans, curAns);
      }

    return ans;
  }

  return 0;
}

Compilation message (stderr)

closing.cpp: In function 'int max_score(int, int, int, long long int, std::vector<int>, std::vector<int>, std::vector<int>)':
closing.cpp:54:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |   for (int i = 0; i < size(U); i++)
      |                   ~~^~~~~~~~~
closing.cpp:104:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  104 |     for (int i = 0; i < size(ext); i++)
      |                     ~~^~~~~~~~~~~
closing.cpp:138:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  138 |           for (int i = 0; i < size(ext); i++)
      |                           ~~^~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 9 / 9
• Subtask 3: 12 / 12
• Subtask 4: 14 / 14
• Subtask 5: 0 / 9
• Subtask 6: 0 / 11
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 17