#include <iostream>
using namespace std;

//SAYED AL MAMUN_LU

int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        int n;
        cin>>n;
        int samp[n];
        for(int i = 0; i<n; i++)
        {
            cin>>samp[i];
        }
        
        int flag = 0;
        
        for(int i = 0; i<n - 1; i++)
        {
            for(int j = i + 1; j<n; j++)
            {
              if(samp[i] == samp[j])
              {
                  flag = 1;
                  break;
              }
              else 
              {
                  flag = 0;
              }
            }
            
            if(flag == 1)
            {
                break;
            }
        }
        
        if(flag == 0)
        {
            cout<<"YES"<<endl;
        }
        else 
        {
            cout<<"NO"<<endl;
        }
        
        
    }
}