Submission #1126613

#	Time	Username	Problem	Language	Result	Execution time	Memory
1126613		brover29	Longest beautiful sequence (IZhO17_subsequence)	C++20	0 / 100	2 ms	320 KiB

subsequence

#include <bits/stdc++.h>
//qwerty47924692
using namespace std;
using ll = int;
const ll N=1e5+29;
const string br="617283";

ll dp[N],a[N],k[N],n,opt[N],op;
vector<ll>pos[257];
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    freopen("subsequence.in","r",stdin);
    freopen("subsequence.out","w",stdout);

    cin>>n;
    for(ll i=1;i<=n;i++){
        cin>>a[i];
    }for(ll i=1;i<=n;i++){
        cin>>k[i];
    }

    ll ans=0;
    if(n<=5000){
        for(ll i=1;i<=n;i++){
            dp[i]=1;
            for(ll j=i-1;j>=0;j--){
                if(__builtin_popcountll(a[i]&a[j])==k[i]){
                    dp[i]=max(dp[i],dp[j]+1);
                    if(dp[i]==dp[j]+1)opt[i]=j;
                }
            }
            ans=max(ans,dp[i]);
            if(ans==dp[i])op=i;
        }
    }else{
        for(ll i=1;i<=n;i++){
            pos[a[i]].push_back(i);
            dp[i]=1;
            for(ll j=1;j<=256;j++){
                if(__builtin_popcountll(j&a[i])==k[i]){

                    for(ll ii:pos[j]){
                       // if(i==3)cout<<(2&3)<<' ';
                        if(dp[ii]+1>dp[i]){
                            dp[i]=dp[ii]+1;
                            opt[i]=ii;
                        }
                    }
                }
            }
            ans=max(ans,dp[i]);
            if(ans==dp[i])op=i;
        }

    }
    cout<<ans<<'\n';
    vector<ll>v;
    ll i=op;
    while(i){
        v.push_back(i);
        i=opt[i];
    }
    reverse(v.begin(),v.end());
    for(ll i:v){
        cout<<i<<' ';
    }
}

Compilation message (stderr)

subsequence.cpp: In function 'int main()':
subsequence.cpp:13:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |     freopen("subsequence.in","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
subsequence.cpp:14:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |     freopen("subsequence.out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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