def test_add():
mammals = LinkedList()
mammals.insert('mouse')
mammals.insert('dog')
mammals.add('cat')
assert mammals.print() == 'dog; mouse; cat; '
class Stack:
def __init__(self):
self.items = LinkedList()
def push(self, value):
"""
Adds the value to the back of the LinkedList
:param value: the value to be added
"""
self.items.add(value)
def pop(self):
"""
Removes the value at the tail
:return: the value of the item removed
"""
if self.items.tail is None:
return None
value = self.items.tail.value
self.items.remove(value)
return value
def peek(self):
"""
:returns: the value of the item at the tail
"""
if not self.items.tail:
return None
return self.items.tail.value
def test_add_one_item(self):
linked_list = LinkedList()
linked_list.add(1)
# assert that the item we inserted is at the head
self.assertEqual(linked_list.head.value, 1)
# assert that when only one item is in the list the head and the tail are the same
self.assertEqual(linked_list.tail.value, 1)
def test_add_multiple():
mammals = LinkedList()
mammals.add('mouse')
mammals.add('dog')
mammals.add('cat')
assert mammals.print() == 'mouse; dog; cat; '
class Queue:
def __init__(self):
"""
Initialize the Queue with an empty LinkedList
"""
self.items = LinkedList()
def is_empty(self):
"""
:returns: True if the LinkedList is empty anf False if it isn't
"""
return self.items.head is None
def enqueue(self, value):
"""
Adds the value to the back of the LinkedList
:param value: the value to be added
"""
self.items.add(value)
def dequeue(self):
"""
Removes the value at the head
:return: the value of the item at the head
"""
value = self.items.head.value
self.items.remove(value)
return value
def peek(self):
"""
:returns: the value of the item at the head
"""
return self.items.head.value
def test_linked_list_expressesion():
ll = LinkedList()
ll.add('apples')
ll.add('bananas')
cap_fruits = [f.upper() for f in ll]
assert cap_fruits == ['APPLES', 'BANANAS']
def test_linked_list_conversion():
ll = LinkedList()
ll.add('apples')
ll.add('bananas')
items = list(ll)
assert items == ['apples', 'bananas']
def test_linked_list_iteration():
ll = LinkedList()
ll.add('apples')
ll.add('bananas')
items = []
for item in ll:
items.append(item)
assert items == ['apples', 'bananas']
def test_find_from_k():
mammals = LinkedList()
mammals.add('orca')
mammals.add('beluga')
mammals.add('porpoise')
mammals.add('otter')
mammals.add('seal')
assert mammals.find_from_end(2) == 'porpoise'
assert mammals.find_from_end(4) == 'orca'
assert mammals.find_from_end(5) is None
class Stack:
def __init__(self):
self.items = LinkedList()
def push(self, value):
self.items.add(value)
def pop(self):
if self.items.tail is None:
return None
value = self.items.tail.value
self.items.remove(value)
return value
def peek(self):
return self.items.tail.value
def test_ll_zip_longer():
ll_1 = LinkedList()
ll_1.add('A')
ll_1.add('B')
ll_1.add('C')
ll_1.add('D')
ll_1.add('E')
ll_2 = LinkedList()
ll_2.add('1')
ll_2.add('2')
ll_2.add('3')
ll_2.add('4')
head = ll_zip(ll_1, ll_2)
assert head.value == 'A'
assert ll_1.print() == 'A; 1; B; 2; C; 3; D; 4; E; '
class CircularQueue:
"""
The CircularQueue uses a LinkedList internally to manage the items
"""
def __init__(self):
"""
Initialize the Queue with an empty LinkedList
"""
self.items = LinkedList()
def is_empty(self):
"""
:returns: True if the LinkedList is empty and False if it isn't
"""
return self.items.head is None
def enqueue(self, value):
"""
Adds the value to the back of the LinkedList
:param value: the value to be added
"""
self.items.add(value)
self.items.tail.next = self.items.head
def dequeue(self):
"""
Removes the value at the head
:return: the value of the item at the head
"""
current_node = self.items.head
if not self.items.head:
return None
self.items.head = self.items.head.next
return current_node.value
def peek(self):
"""
:returns: the value of the item at the head
"""
return self.items.head.value
def test_linked_list_filter():
letters = LinkedList()
letters.add('a')
letters.add('b')
letters.add('c')
letters.add('d')
letters.add('e')
letters.add('f')
letters.add('g')
vowels = 'aeiou'
consonants = [char for char in letters if char not in vowels]
assert consonants == ['b', 'c', 'd', 'f', 'g']
def test_insert_after():
mammals = LinkedList()
mammals.add('whale')
mammals.add('wolf')
mammals.add('ape')
mammals.insert_after('wolf', 'bat')
assert mammals.print() == 'whale; wolf; bat; ape; '
def test_search_item_at_tail(self):
linked_list = LinkedList()
linked_list.add(2)
linked_list.add(4)
linked_list.add(25)
linked_list.add(20)
linked_list.add(12)
self.assertEqual(linked_list.search(12), True)
def test_walk(self):
linked_list = LinkedList()
linked_list.add(2)
linked_list.add(4)
linked_list.add(25)
linked_list.add(20)
linked_list.add(12)
self.assertEqual(linked_list.walk(), [2, 4, 25, 20, 12])
def test_remove_item_not_in_list(self):
linked_list = LinkedList()
linked_list.add(2)
linked_list.add(4)
linked_list.add(25)
linked_list.add(20)
linked_list.add(12)
self.assertEqual(linked_list.remove(0), False)
self.assertEqual(linked_list.walk(), [2, 4, 25, 20, 12])
def test_remove_from_tail(self):
linked_list = LinkedList()
linked_list.add(2)
linked_list.add(4)
linked_list.add(25)
linked_list.add(20)
linked_list.add(12)
self.assertEqual(linked_list.remove(12), True)
self.assertEqual(linked_list.walk(), [2, 4, 25, 20])
def test_remove_from_middle(self):
linked_list = LinkedList()
linked_list.add(2)
linked_list.add(4)
linked_list.add(25)
linked_list.add(20)
linked_list.add(12)
self.assertEqual(linked_list.remove(25), True)
self.assertEqual(linked_list.walk(), [2, 4, 20, 12])
def test_search_item_not_in_list(self):
linked_list = LinkedList()
linked_list.add(2)
linked_list.add(4)
linked_list.add(25)
linked_list.add(52)
linked_list.add(20)
linked_list.add(12)
self.assertEqual(linked_list.search(0), False)
def test_ll_reverse():
ll = LinkedList()
ll.add('A')
ll.add('B')
ll.add('C')
ll.add('D')
ll.add('E')
ll_reverse(ll)
assert ll.print() == 'E; D; C; B; A; '
def test_linked_list_add_one():
ll = LinkedList()
ll.add('apples')
assert ll.head.value == 'apples'
def test_prepend(self):
linked_list = LinkedList()
linked_list.add(1)
linked_list.prepend(20)
self.assertEqual(linked_list.head.value, 20)
self.assertEqual(linked_list.tail.value, 1)
def test_add_two_items(self):
linked_list = LinkedList()
linked_list.add(1)
linked_list.add(22)
self.assertEqual(linked_list.head.next.value, 22)
self.assertEqual(linked_list.head.next.value, linked_list.tail.value)
def test_linked_list_add_two():
ll = LinkedList()
ll.add('apples')
ll.add('bananas')
assert ll.head.value == 'apples'
assert ll.head.nxt.value == 'bananas'