Submission #729301

#	Time	Username	Problem	Language	Result	Execution time	Memory
729301		tch1cherin	Let's Win the Election (JOI22_ho_t3)	C++17	10 / 100	2515 ms	212 KiB

Main

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

void solve() {
  int n, k;
  cin >> n >> k;
  vector<int> a(n), b(n);
  bool good = true;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    good &= b[i] == -1 || b[i] == a[i];
  }
  if (!good) {
    vector<int> order_a(n), order_b(n);
    iota(order_a.begin(), order_a.end(), 0);
    iota(order_b.begin(), order_b.end(), 0);
    sort(order_a.begin(), order_a.end(), [&](int i, int j) {
      return a[i] < a[j];
    });
    long double ans = 1e18;
    for (int mask = 0; mask < (1 << n); mask++) {
      for (int max_c = 0; max_c <= n; max_c++) {
        int c = 1, cnt = 0;
        long double res = 0;
        vector<bool> used(n, false);
        for (int i = 0; i < n; i++) {
          if (((mask >> i) & 1) && b[i] != -1 && c <= max_c) {
            res += (long double)b[i] / c;
            c++;
            cnt++;
            used[i] = true;
          }
        }
        for (int i : order_a) {
          if (cnt < k && !used[i]) {
            res += (long double)a[i] / c;
            cnt++;
          }
        }
        if (cnt >= k) {
          ans = min(ans, res);
        }
      }
    }
    cout << ans << "\n";
  } else {
    vector<int> order(n);
    iota(order.begin(), order.end(), 0);
    sort(order.begin(), order.end(), [&](int i, int j) {
      return a[i] < a[j];
    });
    long double ans = 1e18;
    for (int max_c = 0; max_c <= n; max_c++) {
      int c = 1, cnt = 0;
      long double res = 0;
      for (int i : order) {
        if (a[i] == b[i] && c <= max_c) {
          res += (long double)a[i] / c;
          c++;
          cnt++;
        }
      }
      for (int i : order) {
        if (a[i] != b[i] && cnt < k) {
          res += (long double)a[i] / c;
          cnt++;
        }
      }
      if (cnt >= k) {
        ans = min(ans, res);
      }
    }
    cout << ans << "\n";
  }
}

int main() {
  cout << fixed << setprecision(9);
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  solve();
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 11
• Subtask 4: 0 / 12
• Subtask 5: 0 / 33
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23