Submission #643773

#	Time	Username	Problem	Language	Result	Execution time	Memory
643773		lunchbox1	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	130 ms	1364 KiB

Main

#include <bits/stdc++.h>
using namespace std;
 
#ifdef LOCAL
  #include "debug.h"
#else
  #define debug(...) 0
#endif
 
const int N = 500;
const double INF = 1e18;
 
int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  int n, k;
  cin >> n >> k;
  static array<int, 2> p[N];
  for (int i = 0; i < n; i++) {
    int a, b;
    cin >> a >> b;
    if (b == -1)
      b = 1e9;
    p[i] = {b, a};
  }
  sort(p, p + n);
  static int g[N][N + 1];
  for (int i = 0; i < n; i++) {
    static int t[N];
    for (int j = i; j < n; j++)
      t[j - i] = p[j][1];
    sort(t, t + n - i);
    g[i][0] = 0;
    for (int j = 1; j <= n - i; j++)
      g[i][j] = g[i][j - 1] + t[j - 1];
  }
  double ans = g[0][k];
  for (int t = 0; t <= k; t++) {
    static double f[N + 1];
    for (int i = 0; i <= t; i++)
      f[i] = INF;
    f[0] = 0;
    for (int i = 0; i < n; i++) {
      for (int j = t; j >= 0; j--)
        f[j] = min(f[j] + (double) p[i][1] / (t + 1), j == 0 ? INF : f[j - 1] + (double) p[i][0] / j);
      if (k - i - 1 >= 0)
        ans = min(ans, f[t] + (double) g[i + 1][k - i - 1] / (t + 1));
    }
  }
  cout << fixed << setprecision(12) << 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