Submission #1126270

#	Time	Username	Problem	Language	Result	Execution time	Memory
1126270		tudor_costin	Longest beautiful sequence (IZhO17_subsequence)	C++20	40 / 100	120 ms	2120 KiB

subsequence

#include <bits/stdc++.h>

using namespace std;
ifstream fin("subsequence.in");
ofstream fout("subsequence.out");
const int Nmax=1e5+5;
int a[Nmax],k[Nmax];
int dp[Nmax],prv[Nmax];
int best[260];
void reconst(int x)
{
    if(x==-1) return;
    reconst(prv[x]);
    cout<<x<<' ';
    return;
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0),cout.tie(0);
    int n;
    cin>>n;
    for(int i=1;i<=n;i++) cin>>a[i];
    for(int i=1;i<=n;i++) cin>>k[i];
    if(n<=5000)
    {
        int sol=0,besti=-1;
        for(int i=1;i<=n;i++)
        {
            dp[i]=1;
            prv[i]=-1;
            for(int j=i-1;j>=1;j--)
            {
                int nr=(a[i]&a[j]);
                nr=__builtin_popcount(nr);
                if(nr==k[i] && dp[j]+1>dp[i])
                {
                    dp[i]=dp[j]+1;
                    prv[i]=j;
                }
            }
            if(dp[i]>sol)
            {
                sol=dp[i];
                besti=i;
            }
        }
        cout<<sol<<'\n';
        reconst(besti);
    }
    else
    {
        int sol=0,besti=-1;
        for(int i=1;i<=n;i++)
        {
            dp[i]=1;
            prv[i]=-1;
            for(int j=0;j<=256;j++)
            {
                if(best[j]==0) continue;
                int nr=(a[i]&j);
                nr=__builtin_popcount(nr);
                if(nr==k[i] && dp[best[j]]+1>dp[i])
                {
                    dp[i]=dp[best[j]]+1;
                    prv[i]=best[j];
                }
            }
            if(dp[i]>dp[best[a[i]]]) best[a[i]]=i;
            if(dp[i]>sol)
            {
                sol=dp[i];
                besti=i;
            }
        }
        cout<<sol<<'\n';
        reconst(besti);
    }
    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 16 / 16
• Subtask 3: 17 / 17
• Subtask 4: 0 / 60