1770C - Koxia and Number Theory - CodeForces Solution

#include <bits/stdc++.h>

using namespace std;
#define vi vector<int>
#define vl vector<long long>
#define vs vector<string>
#define vii vector<pair<int,int>>
#define vll vector<pair<long long,long long>>
#define pb push_back
#define ll long long
#define ld long double
#define nl '\n'
#define boost ios::sync_with_stdio(false)
#define mp make_pair
#define se second
#define fi first
#define fore(i, y) for(ll i = 0; i < y; i++)
#define forr(i,x,y) for(int i = x;i<=y;i++)
#define forn(i,y,x) for(ll i = y; i >= x; i--)
#define all(v) v.begin(),v.end()
#define sz(v) v.size()
#define clr(v,k) memset(v,k,sizeof(v))
#define ub upper_bound
#define lb lower_bound

const ll MOD = 1e9 + 7;
const ll INF = 1e18 + 1;

ll gcd(ll a , ll b) {return b ? gcd(b , a % b) : a ;} // greatest common divisor (PGCD)
ll lcm(ll a , ll b) {return (a * b) / gcd(a , b);} // least common multiple (PPCM)

// HERE IS THE SOLUTION
vi primes = {2 , 3 , 5 , 7 , 11 , 13 , 17 , 19 , 23 , 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97};
int main()
{
    cin.tie(0);
    cout.tie(0);
    boost;
    int t;
    cin>>t;
    while(t--)
    {
        int n;
        cin>>n;
        vl v(n);
        fore(i , n)
        {
            cin>>v[i];
        }
        bool acc = 1;
        for(auto p : primes)
        {
            if(p>n)
            {
                break;
            }
            set<ll> st;
            fore(i , n)
            {
                forr(j , i+1 , n-1)
                {
                    if(v[i]==v[j])
                    {
                        acc = 0;
                        break;
                    }
                    if((v[i]%p) == (v[j]%p))
                        st.insert(v[i]%p);
                }
                if(!acc)
                {
                    break;
                }
            }
            if(!acc)break;
            if(sz(st)==p)
            {
                acc = 0;
                break;
            }
        }
        if(acc)
        {
            cout<<"YES"<<nl;
        }
        else
        {
            cout<<"NO"<<nl;
        }
    }
}