#include<bits/stdc++.h>
using namespace std;
#define ll long long
int main(){
	int t;cin>>t;
    while (t--)
    {
        int n;cin>>n;
        set<int>a;
        for(int i=0;i<n;i++){
            int k;cin>>k;
            a.insert(k);
        }
        if(a.size()==n) cout<<"YES"<<endl;
        else cout <<"NO"<<endl;
    }
    return 0;
}