def test_linked_list_includes_value():
"""Test a linked list can be checked for the inclusion of a value."""
value = 1
linked_list = LinkedList()
linked_list.insert(value)
assert linked_list.includes(value)
def test_linked_list_insert_before():
ll = LinkedList()
ll.head = Node(1)
ll.head.next = Node(2)
ll.insert_before(2, 3)
assert ll.head.next.value == 3
assert ll.head.next.next.value == 2
def test_linked_list_insert_after():
ll = LinkedList()
ll.head = Node(1)
ll.head.next = Node(2)
ll.insert_after(1, 4)
assert ll.head.next.value == 4
assert ll.head.next.next.value == 2
def test_linked_list_append():
ll = LinkedList()
ll.head = Node(1)
ll.head.next = Node(2)
ll.append(3)
assert ll.head.next.next.value == 3
assert ll.head.next.next.next == None
def simple_ll():
"""Helper function to return a simple linked list with nodes."""
linked_list = LinkedList()
values = [5, 3, 2]
for value in values:
linked_list.insert(value)
return linked_list
def test_merge_lists_empty_lists():
"""Two linked lists being merged with both empty."""
ll_one = LinkedList()
ll_two = LinkedList()
merged_ll = merge_lists(ll_one, ll_two)
assert merged_ll.head == None
def test_get_linked_list_values():
"""Test a linked list can be represented as a string."""
linked_list = LinkedList()
for i in range(3):
value = i
linked_list.insert(value)
expected = "2, 1, 0"
actual = str(linked_list)
assert actual == expected
def test_kth_from_end_ll_size_1():
"""Test a linked list to return the kth from the end value when the linked list has only one node."""
k = 0
linked_list = LinkedList()
value = 1
linked_list.insert(value)
expected = value
actual = linked_list.kth_from_end(k)
assert actual == expected
def test_merge_lists_empty_second_list():
"""Two linked lists being merged with empty second linked list."""
ll_one = LinkedList()
ll_two = LinkedList()
value = 1
ll_one.insert(value)
merged_ll = merge_lists(ll_one, ll_two)
assert merged_ll.head.value == 1
assert merged_ll.head.next == None
def test_create_linked_list():
"""Test a linked list can be made."""
linked_list = LinkedList()
# Note: I found out about the built-in `vars` function on StackOverflow
# Source: https://stackoverflow.com/questions/109087/how-to-get-instance-variables-in-python
keys = vars(linked_list).keys()
assert len(keys) == 1 and "head" in keys
assert linked_list.head == None
def test_linked_list_insert_before():
"""Test a new value can be inserted before a value already in the linked list."""
linked_list = LinkedList()
value = 1
linked_list.insert(value)
new_value = 2
linked_list.insert_before(value, new_value)
assert linked_list.head.value == new_value
assert linked_list.head.next.value == value
newer_value = 3
linked_list.insert_before(value, newer_value)
assert linked_list.head.next.value == newer_value
assert linked_list.head.next.next.value == value
def test_linked_list_append():
"""Test a value can be appended to a linked list."""
linked_list = LinkedList()
value = 1
linked_list.insert(value)
value = 2
linked_list.append(value)
assert linked_list.head.next.value == value
assert linked_list.head.next.next == None
value = 3
linked_list.append(value)
assert linked_list.head.next.next.value == value
assert linked_list.head.next.next.next == None
def test_linked_list_insert_after():
"""Test a value can be inserted after a value already in the linked list."""
linked_list = LinkedList()
value = 1
linked_list.insert(value)
new_value = 2
linked_list.insert_after(value, new_value)
assert linked_list.head.next.value == new_value
assert linked_list.head.next.next == None
newer_value = 3
linked_list.insert_after(value, newer_value)
assert linked_list.head.next.value == newer_value
assert linked_list.head.next.next.value == new_value
assert linked_list.head.next.next.next == None
def test_merge_lists_second_list_smaller_size():
"""Merge in zipper two linked lists with second list smaller."""
ll_one = LinkedList()
values = [2, 3, 5]
for value in values:
# 5, 3, 2
ll_one.insert(value)
ll_two = LinkedList()
values = [6, 4]
for value in values:
# 4, 6
ll_two.insert(value)
expected = '5, 4, 3, 6, 2'
actual = str(merge_lists(ll_one, ll_two))
assert actual == expected
def test_merge_lists_same_size():
"""Merge in zipper two linked linked of same size."""
ll_one = LinkedList()
values = [2, 3, 5]
for value in values:
# 5, 3, 2
ll_one.insert(value)
ll_two = LinkedList()
values = [9, 6, 4]
for value in values:
# 4, 6, 9
ll_two.insert(value)
expected = '5, 4, 3, 6, 2, 9'
actual = str(merge_lists(ll_one, ll_two))
assert actual == expected
def test_merge_lists_first_list_smaller_size():
"""Merge in zipper two linked lists with first list smaller."""
ll_one = LinkedList()
values = [2, 3]
for value in values:
# 3, 2
ll_one.insert(value)
ll_two = LinkedList()
values = [9, 6, 4]
for value in values:
# 4, 6, 9
ll_two.insert(value)
expected = '3, 4, 2, 6, 9'
actual = str(merge_lists(ll_one, ll_two))
assert actual == expected
def test_insert_linked_list_node():
"""Test a node can be inserted at the head of the linked list."""
value = 1
linked_list = LinkedList()
linked_list.insert(value)
assert linked_list.head.value == value
assert linked_list.head.next == None
value = 2
linked_list.insert(value)
assert linked_list.head.value == 2
assert isinstance(linked_list.head.next, Node)
assert linked_list.head.next.value == 1
assert linked_list.head.next.next == None
def add(self, key, value):
hashed_key_index = self._hash(key)
if not self._bucket[hashed_key_index]:
self._bucket[hashed_key_index] = LinkedList()
self._bucket[hashed_key_index].insert((key, value))
def test_ll_return_collection_of_values():
test = LinkedList()
test.insert('Apple')
test.insert('Cherry')
assert str(test) == "{'Cherry'}->{'Apple'}->None"
def test_ll_includes_false():
test = LinkedList()
test.insert('Apple')
expected = False
actual = test.includes('Banana')
assert actual == expected
def test_ll_includes_true():
test = LinkedList()
test.insert('Apple')
assert test.includes('Apple')
def test_ll_insert_multiple():
test = LinkedList()
test.insert('Apple')
test.insert('Cherry')
assert test.includes('Apple')
assert test.includes('Cherry')
def test_ll_head():
test = LinkedList()
test.insert('Apple')
assert test.head.value == 'Apple'
def test_empty_linked_list():
test = LinkedList()
assert test
def test_head_link():
link_3 = LinkedList()
link_3.insert(5)
actual = str(link_3)
expected = '{ 5 } -> None'
assert actual == expected
from challenges.linked_list.linked_list import LinkedList, Node
link = LinkedList()
def test_empty_list():
actual = link.insert(Node(None))
value = None
assert actual == value
def test_insert_list_with_value_5():
actual = link.insert(Node(5))
value = None
assert actual == value
def test_head_link():
link_3 = LinkedList()
link_3.insert(5)
actual = str(link_3)
expected = '{ 5 } -> None'
assert actual == expected
new_link = LinkedList()
def test_multiple_insert():
new_link.insert('c')
new_link.insert('b')