Submission #872308

#	Time	Username	Problem	Language	Result	Execution time	Memory
872308		MilosMilutinovic	Let's Win the Election (JOI22_ho_t3)	C++14	100 / 100	128 ms	712 KiB

Main

#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, k;
  cin >> n >> k;
  vector<int> a(n);
  vector<int> b(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    if (b[i] == -1) {
      b[i] = (int) 1e9;
   }
  }
  vector<int> order(n);
  iota(order.begin(), order.end(), 0);
  sort(order.begin(), order.end(), [&](int i, int j) {
    if (b[i] != b[j]) {
      return b[i] < b[j];
    } else {
      return a[i] < a[j];
    }
  });
  vector<int> new_a(n);
  vector<int> new_b(n);
  for (int i = 0; i < n; i++) {
    new_a[i] = a[order[i]];
    new_b[i] = b[order[i]];
  }
  a = new_a;
  b = new_b;
  const double inf = 1e9;
  double ans = inf;
  for (int s = 0; s <= k; s++) {
    vector<double> dp(n + 1, inf);
    dp[0] = 0;
    for (int i = 0; i < n; i++) {
      vector<double> new_dp(n + 1, inf);
      for (int j = 0; j <= min(k - s, i); j++) {
        if (i - j < s) {
          new_dp[j] = min(new_dp[j], dp[j] + (double) (b[i] + 0.000) / (double) (i - j + 1));
        } else {
          new_dp[j] = min(new_dp[j], dp[j]);
        }
        new_dp[j + 1] = min(new_dp[j + 1], dp[j] + (double) (a[i] + 0.000) / (double) (s + 1));
      }
      swap(dp, new_dp);
      if (i + 1 >= k) {
        ans = min(ans, dp[k - s]);
      }
    }
  }
  cout << fixed << setprecision(3) << ans << '\n';
  return 0;
}

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