제출 #1085237

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1085237		Timosh	서열 (APIO23_sequence)	C++17	컴파일 에러	0 ms	0 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;
  if (n <= 2e3)
  {
    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;
}

컴파일 시 표준 에러 (stderr) 메시지

sequence.cpp: In function 'int sequence(int, std::vector<int>)':
sequence.cpp:46:3: error: 'last' was not declared in this scope
   46 |   last = 0;
      |   ^~~~