Submission #1085236

#	Time	Username	Problem	Language	Result	Execution time	Memory
1085236		Timosh	Sequence (APIO23_sequence)	C++17	28 / 100	2056 ms	27732 KiB

sequence

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

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set; // find_by_order, order_of_key

int sequence(int n, vector<int> A)
{
  int ans = 1;
  for (int i = 0; i < n; i++)
  {
    ordered_set hm;
    for (int j = i; j < n; j++)
    {
      hm.insert(A[j]);
      int x = *hm.find_by_order((j - i) / 2);
      int y = *hm.find_by_order((j - i + 1) / 2);
      ans = max(ans, (int)hm.order_of_key(x + 1) - (int)hm.order_of_key(x));
      ans = max(ans, (int)hm.order_of_key(y + 1) - (int)hm.order_of_key(y));
    }
  }
  bool works = 1;
  int last = 0;
  for (int i = 0; i < n; i++)
  {
    if (last > A[i])
    {
      for (int j = i; j < n; j++)
      {
        if (last < A[j])
          works = 0;
        last = A[j];
      }
      break;
    }
    last = A[i];
  }
  if (!works)
    return ans;
  last = 0;
  vector<int> cnt(n + 1);
  for (int i = 0; i < n; i++)
  {
    if (last > A[i])
      break;
    cnt[A[i]]++;
    ans = max(ans, cnt[A[i]]);
    last = A[i];
  }
  last = 0;
  for (int i = 1; i <= n; i++)
    cnt[i] = 0;

  for (int i = n - 1; i >= 0; i--)
  {
    if (last > A[i])
      break;
    last = A[i];
    cnt[A[i]]++;
    ans = max(ans, cnt[A[i]]);
  }
  for (int i = 1; i <= n; i++)
    cnt[i] = 0;

  sort(A.begin(), A.end());
  for (int i = 0; i < n; i++)
    cnt[A[i]]++;
  for (int i = n / 2; i < n; i++)
    ans = max(ans, cnt[A[i]]);
  return ans;
}

• Subtask 1: 11 / 11
• Subtask 2: 17 / 17
• Subtask 3: 0 / 7
• Subtask 4: 0 / 12
• Subtask 5: 0 / 13
• Subtask 6: 0 / 22
• Subtask 7: 0 / 18