public void Should_Get_Kth_From_Tail()
{
var input = new LinkedNodeList <int>(new[] { 1, 2, 3, 4, 5 });
var expected = new LinkedNodeList <int>(new[] { 4, 5 });
LinkedNodeUtilities.GetKthFromEnd(input.Head, 2).Should().BeEquivalentTo(expected.Head);
LinkedNodeUtilities.GetKthFromEnd(input.Head, 5).Should().BeEquivalentTo(input.Head);
LinkedNodeUtilities.GetKthFromEnd(input.Head, 1).Should().BeEquivalentTo(input.Last());
}
public void Should_Throw_Exception_For_Invalid_Kth_From_Tail()
{
var input = new LinkedNodeList <int>(new[] { 1, 2, 3, 4, 5 });
var ex = Assert.Throws <Exception>(() => LinkedNodeUtilities.GetKthFromEnd(input.Head, 6));
ex.Message.Should().Be("Invalid k is larger than linked list length");
var ex2 = Assert.Throws <Exception>(() => LinkedNodeUtilities.GetKthFromEnd(input.Head, 0));
ex2.Message.Should().Be("K should be larger than 0");
LinkedNodeUtilities.GetKthFromEnd <int>(null, 0).Should().BeNull();
}