Submission #729309

#	Time	Username	Problem	Language	Result	Execution time	Memory
729309		tch1cherin	Let's Win the Election (JOI22_ho_t3)	C++17	56 / 100	2570 ms	1992 KiB

Main

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

const long double INF = 1e18;

void solve() {
  int n, k;
  cin >> n >> k;
  vector<int> a(n), b(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
  }
  vector<int> order(n);
  iota(order.begin(), order.end(), 0);
  sort(order.begin(), order.end(), [&](int i, int j) {
    return b[i] < b[j];
  });
  vector<int> new_a(n), 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;
  long double ans = INF;
  for (int c = 0; c <= k; c++) {
    vector dp(k + 1, vector<long double>(c + 1, INF));
    dp[0][0] = 0;
    for (int i = 0; i < n; i++) {
      vector new_dp(n + 1, vector<long double>(c + 1, INF));
      for (int j = 0; j <= k; j++) {
        for (int l = 0; l <= c; l++) {
          if (j + 1 <= k && l + 1 <= c && b[i] != -1) {
            new_dp[j + 1][l + 1] = min(new_dp[j + 1][l + 1], dp[j][l] + (long double)b[i] / (l + 1));
          }
          if (j + 1 <= k) {
            new_dp[j + 1][l] = min(new_dp[j + 1][l], dp[j][l] + (long double)a[i] / (c + 1));
          }
          new_dp[j][l] = min(new_dp[j][l], dp[j][l]);
        }
      }
      dp = new_dp;
    }
    for (int i = k; i <= n; i++) {
      ans = min(ans, dp[i][c]);
    }
  }
  cout << ans << "\n";
}

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

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