Submission #896324

#	Time	Username	Problem	Language	Result	Execution time	Memory
896324		vjudge1	Sequence (APIO23_sequence)	C++17	0 / 100	2011 ms	37456 KiB

sequence

#pragma GCC optimize("O3,unroll-loops")
#include <bits/stdc++.h>
#include "sequence.h"
using namespace std;const int LIM = 5e5+1;
vector<int> bit(LIM,0);
int n;
void add(int p,int v) {
  for (int i=p;i<=n;i+=i&-i) bit[i]+=v;
}
int get(int p) {
  int ans = 0;
  for (int i=p;i>0;i-=i&-i) ans+=bit[i];
  return ans;
}

int sequence(int N, std::vector<int> A) {
  n = N;

  vector<int> sme(N+1);
  vector<int> sm(N+1);

  for (int i=1;i<=N;i++) {
    add(A[i-1],1);
    sme[i] = get(A[i-1]);
    sm[i] = get(A[i-1]-1);
  }
  vector<int> poss[N+1];
  for (int i=1;i<=n;i++) poss[A[i-1]].push_back(i);
  int ans = 1;
    for (int i=1;i<=n;i++) {
      int sz = poss[i].size();
      for (int j=0;j<sz;j++) {
        for (int j2=j+1;j2<sz;j2++) {
          int smme = sme[poss[i][j2]]-sme[poss[i][j]]+1;
          int smm = sm[poss[i][j2]]-sm[poss[i][j]];
          int len = (poss[i][j2]-poss[i][j]+1);
          int mid = (len+1)/2;
          if (smme >= mid && smm < mid) ans = max(ans,j2-j+1);
          if (len%2==0 && smm<mid+1 && smme>=mid+1) ans = max(ans,j2-j+1);
        }
      }
    }
  return ans;
}

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