#include <bits/stdc++.h>

#define endl '\n'
#define F first
#define S second
#define pb push_back

typedef long long ll;
typedef unsigned long long ull;

using namespace std;

template<typename T>
void scan(vector<T> &v) {for (T &x : v) cin >> x;}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

#ifdef LUCHADOR
    freopen("/home/joker/Documents/code/in", "r", stdin);
    freopen("/home/joker/Documents/code/out", "w", stdout);
#endif

    int t;
    cin >> t;

    while (t--) {
        int n;
        cin >> n;

        set<int> st;
        for (int i = 0, x; i < n; ++i) {
            cin >> x;
            st.insert(x);
        }

        cout << ((int) st.size() == n ? "YES" : "NO") << endl;
    }

    return 0;
}