#include<bits/stdc++.h>
#define ll    long long int
#define yes   "YES"
#define no    "NO"
#define nl    "\n"
using namespace std;

void solve()
{
    int n;
    cin>>n;
    vector<int>a(n);
    for(int i=1; i<=n; i++)
    {
        cin>>a[i];
    }
    sort(a.begin(),a.end());
    int ans=1;
    for(int i=2;i<=n;i++){
        if(a[i]!=a[i-1])
            ans++;
    }
    if(ans==n)
        cout<<yes<<nl;
    else
        cout<<no<<nl;

}

int main()
{
    int t;
    cin>>t;
    while(t--){
        solve();
    }
}