public static void Test()
{
Solution s = new Solution();
int[] a4 = new[] { 1, 2, 3, 4 };
a4.PrintList();
Console.WriteLine(s.LargestTimeFromDigits(a4) + " is 23:41");
int[] a = new[] { 5, 5, 5, 5 };
a.PrintList();
Console.WriteLine(s.LargestTimeFromDigits(a) + " is \"\"");
int[] a2 = new[] { 2, 3, 5, 9 };
a2.PrintList();
Console.WriteLine(s.LargestTimeFromDigits(a2) + " is 23:59");
int[] a6 = new[] { 0, 0, 0, 0 };
a6.PrintList();
Console.WriteLine(s.LargestTimeFromDigits(a6) + " is \"\"");
}