Submission #864329

#	Time	Username	Problem	Language	Result	Execution time	Memory
864329		NeroZein	Port Facility (JOI17_port_facility)	C++17	0 / 100	1 ms	348 KiB

port_facility

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

#ifdef Nero
#include "Deb.h"
#else
#define deb(...)
#endif

const int md = 1e9 + 7; 

int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  cin >> n;
  vector<pair<int, int>> a(n); 
  for (int i = 0; i < n; ++i) {
    cin >> a[i].first >> a[i].second; 
  }
  sort(a.begin(), a.end()); 
  vector<int> o(2 * n + 1);
  for (int i = 0; i < n; ++i) {
    o[a[i].second] = i; 
  }
  int ans = 1; 
  set<int> active; 
  vector<bool> col(n); 
  vector<set<int>> se(2); 
  for (int i = 0; i < n; ++i) {
    while (!active.empty() && *active.begin() < a[i].first) {
      int ind = o[*active.begin()]; 
      se[col[ind]].erase(a[ind].second); 
      active.erase(active.begin()); 
    }
    bool one = se[0].empty() || *se[0].begin() > a[i].second; 
    bool two = se[1].empty() || *se[1].begin() > a[i].second; 
    if (one && two) {
      col[i] = 0;
      ans = (ans * 2) % md;
      se[0].insert(a[i].second);
    } else if (one) {
      col[i] = 0;
      se[0].insert(a[i].second);
    } else if (two) {
      col[i] = 1;
      se[1].insert(a[i].second);
    } else {
      ans = 0;
      break; 
    }
    active.insert(a[i].second); 
  }
  cout << ans << '\n'; 
  return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22