Submission #537927

#	Time	Username	Problem	Language	Result	Execution time	Memory
537927		theysoldtheworld	Sure Bet (CEOI17_sure)	C++14	100 / 100	105 ms	5804 KiB

sure

#include <bits/stdc++.h>
 
using namespace std;
 
double Get(vector<double> a , vector<double> b) {
  int n = (int)a.size();
  double h = 0;
  double ans = 0;
  vector<double> pref(n);
  for (int i = 0 ; i < n ; i++) {
    pref[i] = (i > 0 ? pref[i - 1] : 0) + b[i];
  }
  auto F = [&](int mid , int i) {
    return min(h - (mid + 1) , pref[mid] - (i + 1));
  };
  int last_pos = -1;
  for (int i = 0 ; i < n ; i++) {
    h += a[i];
    int l = -1 , r = n;
    while (r - l > 1) {
      int mid = l + (r - l) / 2;
      if (F(mid , i) > F(mid + 1 , i)) {
        r = mid;
      }
      else {
        l = mid;
      }
    }
    assert(l + 1 >= last_pos);
    last_pos = l + 1;
    ans = max(ans , F(l + 1 , i));
  }
  return ans;
}
 
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vector<double> a(n) , b(n);
  for (int i = 0 ; i < n ; i++) {
    cin >> a[i] >> b[i];
    a[i] -= 1; 
    b[i] -= 1;
  }
  sort(a.rbegin() , a.rend());
  sort(b.rbegin() , b.rend());
  double ans = max(Get(a , b) , Get(b , a));
  cout << fixed << setprecision(4) << ans << '\n';
  return 0; 
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 40 / 40