Submission #447471

#	Time	Username	Problem	Language	Result	Execution time	Memory
447471		prvocislo	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	2 ms	1032 KiB

books

#include <bits/stdc++.h>
#include "books.h"
typedef long long ll;
using namespace std;

vector<ll> b;
ll query(int i)
{
  if (b[i] == -1) b[i] = skim(i+1);
  return b[i];
}
void solve(int n, int k, ll a, int s)
{
  b.assign(n, -1);
  int lo = 0, hi = n;
  while (lo < hi)
  {
    int mid = (lo+hi)/2;
    if (query(mid) >= a) hi = mid;
    else lo = mid + 1;
  }
  int m = lo;
  if (lo != n)
  {
    ll sum = query(m);
    for (int i = 0; i < k-1; i++) sum += query(i);
    if (a <= sum && sum <= 2*a)
    {
      vector<int> v;
      for (int i = 0; i < k-1; i++) v.push_back(i+1);
      v.push_back(m+1);
      answer(v);
      return;
    }
  }
  vector<pair<ll, int> > v;
  for (int i = 0; i < min(k, m); i++) v.push_back({query(i), i});
  for (int i = max(0, m-k); i < m; i++) 
    v.push_back({query(i), i});
  sort(v.begin(), v.end());
  v.erase(unique(v.begin(), v.end()), v.end());
  for (int i = 0; i+k-1 < v.size(); i++)
  {
    ll sum = 0; vector<int> in;
    for (int j = i; j < i+k; j++)
    {
      sum += v[j].first;
      in.push_back(v[j].second+1);
    }
    if (a <= sum && sum <= 2*a) answer(in);
  }
  impossible();
}

Compilation message (stderr)

books.cpp: In function 'void solve(int, int, ll, int)':
books.cpp:42:25: 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]
   42 |   for (int i = 0; i+k-1 < v.size(); i++)
      |                   ~~~~~~^~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 20 / 20
• Subtask 7: 20 / 20