public static void Test()
{
Solution s = new Solution();
//Console.WriteLine(s.NumPoints());
s.Intersect(new int[] { 1, 2 }, new int[] { 1, 1 }).PrintList();
s.Intersect(new int[] { 1 }, new int[] { }).PrintList();
s.Intersect(new int[] { 1, 2, 2, 1 }, new int[] { 2, 2 }).PrintList();
s.Intersect(new int[] { 4, 9, 5 }, new int[] { 9, 4, 9, 8, 4 }).PrintList();
}