题解

#include <bits/stdc++.h>
using namespace std;
int main()
{
	int t;
	cin >> t;
	
	for (int i = 0; i < t; i++)
	{
		int n;
		cin >> n;
		int arr[n];
		
		for (int j = 0; j < n; j++)
			cin >> arr[j];
		
		int sum = 0;
		
		for (int a = 0; a < n; a++)
		{
			int count = arr[a];

			for (int b = a + 1; b < n; b++)
				if (arr[b] == arr[a])
					sum = 1;
		}
		if (sum == 0)
			cout << "YES" << endl;
		else
			cout << "NO" << endl; 
	}
	
	return 0;
}