Submission #649437

#	Time	Username	Problem	Language	Result	Execution time	Memory
649437		cadmiumsky	A Difficult(y) Choice (BOI21_books)	C++14	45 / 100	35 ms	336 KiB

books

#include <bits/stdc++.h>

#include "books.h"

using namespace std;
using ll = long long;

const int nmax = 1e5 + 5;

namespace QUERY {
  ll v[nmax];
  set<int> ind;
  ll query(int x) {
    if(v[x] == 0) {
      v[x] = skim(x);
      ind.insert(x);
    }
    return v[x];
  }
}

ll n, k, a, s;

ll fmin(ll x) {
  return x * k + k * (k - 1) / 2;
}
ll fmax(ll x) {
  return x * k - k * (k - 1) / 2;
}
using namespace QUERY;
#define list shsflkhsdsdhsd
vector<ll> list;
vector<int> sol;
void mksolve(int lp, ll sum = 0) {
  if(sum > 2 * a) return;
  if(sol.size() == k) {
    if(sum >= a) {
      answer(sol);
    }
    return;
  }
  lp++;
  for(int i = lp; i + k - sol.size() <= list.size(); i++) {
    sol.push_back(list[i]);
    sum += v[list[i]];
    mksolve(i, sum);
    sol.pop_back();
    sum -= v[list[i]];
  }
  return;
}

void solve(int _N, int _K, long long _A, int _S) {
  n = _N;
  k = _K;
  a = _A;
  s = _S;
  s = min(40LL, s);
  int l = n;
  for(int i = 16; i >= 0; i--) {
    if(l - (1 << i) <= 0) continue;
    if(fmin(query(l - (1 << i))) > 2 * a)
      l -= (1 << i);
    s--;
  }
  //cerr << l << ' ' << s << '\n';
  if(l == 1)
    impossible();
  s = min(s, 25LL);
  if(query(l) - query(l - 1) >= a) {
    list.push_back(l);
    for(int i = 1; i <= n && s > 0; s--, i++)
      query(i),
      list.push_back(i);
  }
  else {
    int lim = (s + 3) / 2;
    //cerr << lim << ' ' << s << '\n';
    for(int i = l; i > 0 && lim > 0; s--, i--, lim--)
      list.push_back(i),
      query(i);
    for(int i = max(1, l); s > 0 && i <= n; i++, s--)
      list.push_back(i),
      query(i);
  }
  sort(list.begin(), list.end());
  list.resize(unique(list.begin(), list.end()) - list.begin());
  sol.reserve(40);
  mksolve(-1);
  impossible();
}

Compilation message (stderr)

books.cpp: In function 'void mksolve(int, ll)':
books.cpp:36:17: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   36 |   if(sol.size() == k) {
      |      ~~~~~~~~~~~^~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3: 10 / 10
• Subtask 4: 15 / 15
• Subtask 5: 0 / 15
• Subtask 6: 20 / 20
• Subtask 7: 0 / 20