Submission #977820

#	Time	Username	Problem	Language	Result	Execution time	Memory
977820		Nexus	Sequence (APIO23_sequence)	C++17	28 / 100	2037 ms	10324 KiB

sequence

#include "sequence.h"
#include <bits/stdc++.h>
#define ll long long
#define mid (r+l)/2
 
using namespace std;
 
const ll N=3e5+9,M=2e18+9,mod=1e9+7;

ll tr[N],n,x,y,L,R,m;

void up(ll i,ll l,ll r,ll ind,ll v)
{
    if(l==r)
    {
        tr[i]+=v;
        return;
    }
    if(ind<=mid)up(2*i,l,mid,ind,v);
    else up(2*i+1,mid+1,r,ind,v);
    tr[i]=tr[2*i]+tr[2*i+1];
}

ll q(ll i,ll l,ll r,ll s,ll e)
{
    if(s<=l && r<=e)return tr[i];
    if(s<=mid && mid<e)return q(2*i,l,mid,s,e)+q(2*i+1,mid+1,r,s,e);
    if(s<=mid)return q(2*i,l,mid,s,e);
    return q(2*i+1,mid+1,r,s,e);
}
 
int sequence(int N, vector<int> A) {
 ll ans=1;
 
 for(ll i=0;i<N;++i)
 {
     for(ll j=i;j<N;++j)
     {
         up(1,0,N,A[j],1);
         if((j-i+1)&1)
         {
             L=0,R=N+1,x=(j-i+1)/2+1;
             while(R-L>1)
             {
                 m=(R+L)/2;
                 if(q(1,0,N,0,m)<x)L=m;else R=m;
             }
             ans=max(ans,q(1,0,N,L+1,L+1));
         }
         else
         {
             
             L=0,R=N+1,x=(j-i+1)/2;
             while(R-L>1)
             {
                 m=(R+L)/2;
                 if(q(1,0,N,0,m)<x)L=m;else R=m;
             }
             ans=max(ans,q(1,0,N,L+1,L+1));
             
             L=0,R=N+1,x=(j-i+1)/2+1;
             while(R-L>1)
             {
                 m=(R+L)/2;
                 if(q(1,0,N,0,m)<x)L=m;else R=m;
             }
             ans=max(ans,q(1,0,N,L+1,L+1));
         }
     }
     for(ll j=i;j<N;++j)up(1,0,N,A[j],-1);
  }
  return ans;
}

/*
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
 
    cin>>n;
    vector<int>v(n);
    for(auto &i:v)cin>>i;
    cout<<sequence(n,v);
}
*/

• 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