Language: C++

#include<bits/stdc++.h>
using namespace std;

using ll=__int128;
const ll INF=1e15;
int main(){
    vector<vector<ll>> comb(300,vector<ll>(300,0));
    for(int i=0;i<300;i++){
        comb[i][0]=1;
        comb[i][i]=1;
    }
    for(int i=1;i<300;i++){
        for(int j=1;j<i;j++){
            comb[i][j]=min(comb[i-1][j]+comb[i-1][j-1],INF);
        }
    }
    long long bufn;
    cin>>bufn;
    ll n=bufn;
    vector<int> ans;

    auto calcPatSingle=[&](int len){
        ll sum=0;
        for(int k=2;k<=len;k+=2){
            sum+=comb[len][k];
        }
        return sum;
    };
    auto calcPatCross=[&](int l1,int l2){
        return comb[2*l1][l1]*comb[2*l2][l2];
    };
    int num=1;
    while(n){
        int besti=-1;
        int bestj=-1;
        ll bestSum=0;
        for(int i=0;i<=41;i++){
            for(int j=0;j<i;j++){
                ll sum=calcPatSingle(i)+calcPatSingle(j)+calcPatCross(i,j);
                if(sum<=n && double(bestSum)/(besti+bestj)<double(sum)/(j+j)){
                    besti=i,bestj=j;
                    bestSum=sum;
                }
                
            }
        }
        n-=bestSum;
        for(int k=0;k<2;k++){
            for(int i=0;i<besti;i++){
                ans.push_back(num);
            }
            for(int j=0;j<bestj;j++){
                ans.push_back(num+1);                
            }
        }
        num+=2;
    }

    cout<<ans.size()<<endl;
    for(int i=0;i<ans.size();i++){
        cout<<ans[i]<<(i+1==ans.size() ? "\n" : " ");
    }
    return 0;
}#include<bits/stdc++.h>
using namespace std;

using ll=__int128;
const ll INF=1e15;
int main(){
    vector<vector<ll>> comb(300,vector<ll>(300,0));
    for(int i=0;i<300;i++){
        comb[i][0]=1;
        comb[i][i]=1;
    }
    for(int i=1;i<300;i++){
        for(int j=1;j<i;j++){
            comb[i][j]=min(comb[i-1][j]+comb[i-1][j-1],INF);
        }
    }
    long long bufn;
    cin>>bufn;
    ll n=bufn;
    vector<int> ans;

    auto calcPatSingle=[&](int len){
        ll sum=0;
        for(int k=2;k<=len;k+=2){
            sum+=comb[len][k];
        }
        return sum;
    };
    auto calcPatCross=[&](int l1,int l2){
        return comb[2*l1][l1]*comb[2*l2][l2];
    };
    int num=1;
    while(n){
        int besti=-1;
        int bestj=-1;
        ll bestSum=0;
        for(int i=0;i<=41;i++){
            for(int j=0;j<i;j++){
                ll sum=calcPatSingle(i)+calcPatSingle(j)+calcPatCross(i,j);
                if(sum<=n && double(bestSum)/(besti+bestj)<double(sum)/(j+j)){
                    besti=i,bestj=j;
                    bestSum=sum;
                }
                
            }
        }
        n-=bestSum;
        for(int k=0;k<2;k++){
            for(int i=0;i<besti;i++){
                ans.push_back(num);
            }
            for(int j=0;j<bestj;j++){
                ans.push_back(num+1);                
            }
        }
        num+=2;
    }

    cout<<ans.size()<<endl;
    for(int i=0;i<ans.size();i++){
        cout<<ans[i]<<(i+1==ans.size() ? "\n" : " ");
    }
    return 0;
}

Compiler output:
a.cc:64:2: error: stray '#' in program
   64 | }#include<bits/stdc++.h>
      |  ^
a.cc:64:3: error: 'include' does not name a type
   64 | }#include<bits/stdc++.h>
      |   ^~~~~~~
a.cc:68:10: error: redefinition of 'const ll INF'
   68 | const ll INF=1e15;
      |          ^~~
a.cc:5:10: note: 'const ll INF' previously defined here
    5 | const ll INF=1e15;
      |          ^~~
a.cc:69:5: error: redefinition of 'int main()'
   69 | int main(){
      |     ^~~~
a.cc:6:5: note: 'int main()' previously defined here
    6 | int main(){
      |     ^~~~
a.cc: In lambda function:
a.cc:92:23: error: mangling of 'main()::<lambda(int, int)>' as '_ZZ4mainENKUliiE_clEii' conflicts with a previous mangle
   92 |     auto calcPatCross=[&](int l1,int l2){
      |                       ^
a.cc:29:23: note: previous mangling 'main()::<lambda(int, int)>'
   29 |     auto calcPatCross=[&](int l1,int l2){
      |                       ^
a.cc:92:23: note: a later '-fabi-version=' (or =0) avoids this error with a change in mangling
   92 |     auto calcPatCross=[&](int l1,int l2){
      |                       ^