Problem: 2049C - MEX Cycle
Language: c++20 

Code 1:
// بسم الله الرحمن الرحيم



#include <bits/stdc++.h>

//#include <ext/pb_ds/assoc_container.hpp>

//#include <ext/pb_ds/tree_policy.hpp>

#define Hesham ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)

//#define ordered_set tree<ll,null_type,less_equal<>,rb_tree_tag,tree_order_statistics_node_update>

#define fll(i,a,b) for(long long i=a;i<b;i++)

#define fllm(i,a,b) for(long long i=a;i>=b;i--)

#define f(b,a) cout << fixed << setprecision(b) << a << endl;

#define rall(x) x.rbegin(),x.rend()

#define MOD 1000000007

#define sub_mod(a,b,m) ((((a)%m)-((b)%m)+m)%m)

#define add_mod(a,b,m) ((((a)%m)+((b)%m))%m)

#define mult_mod(a,b,m) ((((a)%m)*((b)%m))%m)

#define pi 3.14159265358979323846

#define all(x) x.begin(),x.end()

#define ull unsigned long long

#define ld long double

#define ll long long

#define sz(s) s.size()

#define yes cout << "YES" << nl

#define no cout << "NO" << nl

#define F first

#define S second

#define nl '\n'



using namespace std;

//using namespace __gnu_pbds;

const int m=998244353;

const int maxn=200000;

vector<ll>fact(maxn,1),inv(maxn,1);

vector<bool>sieve(20+1,1);

vector<ll>spf(20);



ll dx[] = {0, -1, 1, 0};

ll dy[] = {1, 0, 0, -1};



bool isPrime(ll n)

{

    if(n==1||(n%2==0&&n!=2)) return false;

    for(ll j=2;j*j<=n;j++)

    {

        if(n%j==0)

        {

            return false;

        }

    }

    return true;

}



void sev()

{

    for(ll i=2;i*i<=maxn;i++)

    {

        if(sieve[i])

        {

            for(ll j=i*i;j<=maxn;j+=i)

            {

                sieve[j]=0;

            }

        }

    }

    sieve[1]=0,sieve[0]=0;

}



void smallestpf()

{

    spf[1]=1;

    fll(i,2,maxn) spf[i]=i;

    for(ll i=4;i<maxn;i+=2) spf[i]=2;

    for(ll i=3;i*i<maxn;i++)

    {

        if(spf[i]==i)

        {

            for(ll j=i*i;j<maxn;j+=i)

                if(spf[j]==j) spf[j]=i;

        }

    }

}



vector<ll>getf(ll n)

{

    vector<ll>ret;

    while(n!=1)

    {

        ret.push_back(spf[n]);

        n=n/spf[n];

    }

    return ret;

}



bool comp(pair<ll,ll>p1,pair<ll,ll>p2)

{

    return p1.S<p2.S;

}



ll fastpower(ll x,ll n,ll m)

{

    ll res=1;

    while(n>0)

    {

        if(n%2!=0) res=(res%m*x%m)%m,n--;

        else x=(x%m*x%m)%m,n/=2;

    }

    return res;

}



vector<ll>presum(vector<ll> &v)

{

    vector<ll>p(v.size());

    fll(i,0,v.size())

    {

        if(i==0) p[i]=v[i];

        else p[i]=v[i]+p[i-1];

    }

    return p;

}



vector<ll>primefactor(ll n)

{

    ll cn=0; vector<ll>v;

    while(n%2==0)

    {

        v.push_back(2); n/=2;

    }

    for(ll j=3;j*j<=n;j+=2)

    {

        while(n%j==0)

        {

            v.push_back(j);

            n/=j;

        }

    }

    if(n>2) v.push_back(n);



    return v;

}



vector<ll>divisors(ll n)

{

    vector<ll>c;

    for(ll i=1;i*i<=n;i++)

    {

        if(n%i==0)

        {

            c.push_back(i);

            if(n/i!=i) c.push_back(n/i);

        }

    }

    return c;

}



ll lcm(ll a,ll b)

{

    ll k=(a*b)/__gcd(a,b);

    return k;

}



ll arteq(ll l,ll r,ll p)

{

    ll k=((r-l)/p)+1;

    ll h=k*(l*2+(k-1)*p); h/=2;

    return h;

}



ll binpow(ll a,ll b,ll p=m)

{

    ll res=1;

    while(b>0)

    {

        if(b&1) res*=a,res%=p;

        a*=a,a%=p;

        b>>=1;

    }

    return res;

}



void solve()

{

    ll n,x,y,cn=0; cin >> n >> x >> y; x--,y--; vector<ll>v(n);

    fll(i,0,n)

    {

        if(i==n-1) v[i]=2;

        else v[i]=i%2;

    }

    if(v[x]==v[y]) v[y]=2;

    fll(i,0,n)

    {

        ll a=i-1,b=i+1;

        if(b==n) b=0;

        if(a==-1) a=n-1;

        ll mn,mx,c=0; vector<ll>cx;

        if(i==x) cx={v[a],v[b],v[y]};

        else if(i==y) cx={v[a],v[b],v[x]};

        else cx={v[a],v[b]};

        sort(all(cx));

        fll(j,0,sz(cx)) if(c==cx[j]) c++;

        v[i]=c;

    }

    fll(i,0,n)

    {

        ll a=i-1,b=i+1;

        if(b==n) b=0;

        if(a==-1) a=n-1;

        ll mn,mx,c=0; vector<ll>cx;

        if(i==x) cx={v[a],v[b],v[y]};

        else if(i==y) cx={v[a],v[b],v[x]};

        else cx={v[a],v[b]};

        sort(all(cx));

        fll(j,0,sz(cx)) if(c==cx[j]) c++;

        v[i]=c;

    }

    fll(i,0,n) cout << v[i] << " "; cout << nl;



}



int main()

{

    Hesham;

    // freopen("army.in","r",stdin);

    // freopen("output.out","w",stdout);

    ll t=1;

    cin >> t;

    while(t--) solve();



  return 0;

}

Code 2:
// بسم الله الرحمن الرحيم



#include <bits/stdc++.h>

//#include <ext/pb_ds/assoc_container.hpp>

//#include <ext/pb_ds/tree_policy.hpp>

#define Hesham ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)

//#define ordered_set tree<ll,null_type,less_equal<>,rb_tree_tag,tree_order_statistics_node_update>

#define fll(i,a,b) for(long long i=a;i<b;i++)

#define fllm(i,a,b) for(long long i=a;i>=b;i--)

#define f(b,a) cout << fixed << setprecision(b) << a << endl;

#define rall(x) x.rbegin(),x.rend()

#define MOD 1000000007

#define sub_mod(a,b,m) ((((a)%m)-((b)%m)+m)%m)

#define add_mod(a,b,m) ((((a)%m)+((b)%m))%m)

#define mult_mod(a,b,m) ((((a)%m)*((b)%m))%m)

#define pi 3.14159265358979323846

#define all(x) x.begin(),x.end()

#define ull unsigned long long

#define ld long double

#define ll long long

#define sz(s) s.size()

#define yes cout << "YES" << nl

#define no cout << "NO" << nl

#define F first

#define S second

#define nl '\n'



using namespace std;

//using namespace __gnu_pbds;

const int m=998244353;

const int maxn=200000;

vector<ll>fact(maxn,1),inv(maxn,1);

vector<bool>sieve(20+1,1);

vector<ll>spf(20);



ll dx[] = {0, -1, 1, 0};

ll dy[] = {1, 0, 0, -1};



bool isPrime(ll n)

{

    if(n==1||(n%2==0&&n!=2)) return false;

    for(ll j=2;j*j<=n;j++)

    {

        if(n%j==0)

        {

            return false;

        }

    }

    return true;

}



void sev()

{

    for(ll i=2;i*i<=maxn;i++)

    {

        if(sieve[i])

        {

            for(ll j=i*i;j<=maxn;j+=i)

            {

                sieve[j]=0;

            }

        }

    }

    sieve[1]=0,sieve[0]=0;

}



void smallestpf()

{

    spf[1]=1;

    fll(i,2,maxn) spf[i]=i;

    for(ll i=4;i<maxn;i+=2) spf[i]=2;

    for(ll i=3;i*i<maxn;i++)

    {

        if(spf[i]==i)

        {

            for(ll j=i*i;j<maxn;j+=i)

                if(spf[j]==j) spf[j]=i;

        }

    }

}



vector<ll>getf(ll n)

{

    vector<ll>ret;

    while(n!=1)

    {

        ret.push_back(spf[n]);

        n=n/spf[n];

    }

    return ret;

}



bool comp(pair<ll,ll>p1,pair<ll,ll>p2)

{

    return p1.S<p2.S;

}



ll fastpower(ll x,ll n,ll m)

{

    ll res=1;

    while(n>0)

    {

        if(n%2!=0) res=(res%m*x%m)%m,n--;

        else x=(x%m*x%m)%m,n/=2;

    }

    return res;

}



vector<ll>presum(vector<ll> &v)

{

    vector<ll>p(v.size());

    fll(i,0,v.size())

    {

        if(i==0) p[i]=v[i];

        else p[i]=v[i]+p[i-1];

    }

    return p;

}



vector<ll>primefactor(ll n)

{

    ll cn=0; vector<ll>v;

    while(n%2==0)

    {

        v.push_back(2); n/=2;

    }

    for(ll j=3;j*j<=n;j+=2)

    {

        while(n%j==0)

        {

            v.push_back(j);

            n/=j;

        }

    }

    if(n>2) v.push_back(n);



    return v;

}



vector<ll>divisors(ll n)

{

    vector<ll>c;

    for(ll i=1;i*i<=n;i++)

    {

        if(n%i==0)

        {

            c.push_back(i);

            if(n/i!=i) c.push_back(n/i);

        }

    }

    return c;

}



ll lcm(ll a,ll b)

{

    ll k=(a*b)/__gcd(a,b);

    return k;

}



ll arteq(ll l,ll r,ll p)

{

    ll k=((r-l)/p)+1;

    ll h=k*(l*2+(k-1)*p); h/=2;

    return h;

}



ll binpow(ll a,ll b,ll p=m)

{

    ll res=1;

    while(b>0)

    {

        if(b&1) res*=a,res%=p;

        a*=a,a%=p;

        b>>=1;

    }

    return res;

}



void solve()

{

    ll n,x,y,cn=0; cin >> n >> x >> y; x--,y--; vector<ll>v(n);

    fll(i,0,n)

    {

        if(i==n-1) v[i]=2;

        else v[i]=i%2;

    }

    if(v[x]==v[y]) v[y]=2;

    fll(i,0,n)

    {

        ll a=i-1,b=i+1;

        if(b==n) b=0;

        if(a==-1) a=n-1;

        ll mn,mx,c=0; vector<ll>cx;

        if(i==x) cx={v[a],v[b],v[y]};

        else if(i==y) cx={v[a],v[b],v[x]};

        else cx={v[a],v[b]};

        sort(all(cx));

        fll(j,0,sz(cx)) if(c==cx[j]) c++;

        v[i]=c;

    }

    fll(i,0,n) cout << v[i] << " "; cout << nl;



}



int main()

{

    Hesham;

    // freopen("army.in","r",stdin);

    // freopen("output.out","w",stdout);

    ll t=1;

    cin >> t;

    while(t--) solve();



  return 0;

}

Answer: 1