Submission #702840

#	Time	Username	Problem	Language	Result	Execution time	Memory
702840		veehz	Strange Device (APIO19_strange_device)	C++17	5 / 100	1836 ms	168608 KiB

strange_device

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

typedef long long ll;

vector<ll> original;

int main() {
  ll n, a, b;
  cin >> n >> a >> b;
  vector<pair<ll, ll>> v(n);
  for (int i = 0; i < n; i++) cin >> v[i].first >> v[i].second;
  for (int i = 0; i < n; i++) {
    original.push_back(v[i].first);
    original.push_back(v[i].second);
    original.push_back(v[i].second + 1);
  }
  sort(original.begin(), original.end());
  original.resize(unique(original.begin(), original.end()) - original.begin());
  map<ll, ll> mp;
  for (int i = 0; i < original.size(); i++) mp[original[i]] = i;

  ll gc = __gcd(a, b + 1);
  bool smallEnough = (__int128_t(a) / gc * __int128_t(b) <= LONG_LONG_MAX);
  ll cy = smallEnough ? a / gc * b : 0;

  vector<int> pre(original.size() + 1);
  for (int i = 0; i < n; i++) {
    auto& p = v[i];
    ll l = p.first, r = p.second;
    if (smallEnough && r - l + 1 >= cy) {
      cerr << "FULL" << endl;
      cout << cy << endl;
      return 0;
    }

    auto add = [&](ll l, ll r) {
      pre[mp[l]]++;
      pre[mp[r + 1]]--;
    };

    if (smallEnough) {
      l %= cy;
      r %= cy;
      if (l > r) {
        add(l, cy - 1);
        add(0, r);
      } else {
        add(l, r);
      }
    } else {
      add(l, r);
    }
  }

  //   for (int i = 1; i < pre.size(); i++) pre[i] += pre[i - 1];
  int cur = 0;
  ll ans = 0;
  for (int i = 0; i < pre.size() - 1; i++) {
    cur += pre[i];
    if (cur > 0) ans += original[i + 1] - original[i];
  }
  cout << ans << endl;
}

Compilation message (stderr)

strange_device.cpp: In function 'int main()':
strange_device.cpp:21:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |   for (int i = 0; i < original.size(); i++) mp[original[i]] = i;
      |                   ~~^~~~~~~~~~~~~~~~~
strange_device.cpp:59:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |   for (int i = 0; i < pre.size() - 1; i++) {
      |                   ~~^~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 5 / 5
• Subtask 3: 0 / 5
• Subtask 4: 0 / 5
• Subtask 5: 0 / 5
• Subtask 6: 0 / 20
• Subtask 7: 0 / 20
• Subtask 8: 0 / 30