def test_kth_is_in_ll_somewhere():
ll = LinkedList([1, 2, 3, 4])
assert ll.kth_from_end(0) == 4
assert ll.kth_from_end(1) == 3
assert ll.kth_from_end(3) == 1
def test_ll_is_size_one():
ll = LinkedList([100])
assert ll.kth_from_end(0) == 100
def test_k_is_equal_to_list_length():
ll = LinkedList([1, 2, 3])
val = 3
with pytest.raises(Exception) as context:
ll.kth_from_end(val)
assert str(context.value) == f'Invalid index: {val} is out of range on linked list'
def test_k_is_negative():
ll = LinkedList()
val = -1
with pytest.raises(Exception) as context:
ll.kth_from_end(val)
assert str(context.value) == f'Invalid index: {val} is out of range on linked list'
def test_k_is_greater_than_list_length():
ll = LinkedList()
val = 1
with pytest.raises(Exception) as context:
ll.kth_from_end(val)
assert str(context.value) == f'Invalid index: {val} is out of range on linked list'