def add(self, val: any) -> None:
"""Add a new node with Breadth first approach
Args:
val (any): Value to add
"""
new_node = Node(val)
if self.root:
q = Queue()
q.enqueue(self.root)
while not q.is_empty():
node = q.dequeue()
if node.left:
q.enqueue(node.left)
else:
node.left = new_node
return
if node.right:
q.enqueue(node.right)
else:
node.right = new_node
return
else:
self.root = new_node
def test_dequeue_when_empty():
# TODO it should raise an exception when dequeueing an empty queue
q = Queue()
with pytest.raises(InvalidOperationError) as e:
q.dequeue()
assert str(e.value) == "Method not allowed on empty collection"
def fizz_buzz_tree(tree: object) -> object:
"""Traverse the given k-ary tree and replace its values in FizzBuzz manner
Args:
tree (object): k-ary tree
Returns:
object: new k-ary tree
"""
output = Tree()
if tree.root:
q1 = q2 = Queue()
q1.enqueue(tree.root)
output.root = Node(fizz_buzz(tree.root.val))
q2.enqueue(output.root)
while not q1.is_empty():
el1, el2 = q1.dequeue(), q2.dequeue()
for child in el1.children:
q1.enqueue(child)
new_el = Node(fizz_buzz(child.val))
el2.children.append(new_el)
q2.enqueue(new_el)
return output
def test_dequeue_when_full():
q = Queue()
q.enqueue("apples")
q.enqueue("bananas")
actual = q.dequeue()
expected = "apples"
assert actual == expected
def test_queue_peek():
value = 1
node = Node(value)
queue = Queue(node)
actual = queue.peek()
expected = value
assert actual == expected
def test_dequeue_one():
queue = Queue()
queue.enqueue(2)
queue.enqueue(1)
actual = queue.dequeue()
expected = 2
assert actual == expected
def test_dequeue():
q = Queue()
q.enqueue('apple')
q.dequeue()
actual = q.is_empty()
expected = True
assert actual == expected
def breadth_first(self, start: Vertex) -> set:
"""Traverse a graph in breadth-first manner and return a set of Vertices
Args:
start (Vertex): Starting point of the traversal
Raises:
KeyError: If provided vertex is not part of the graph
Returns:
set: Set of vertices
"""
q = Queue()
output = set()
if not start in self.adjacency_list:
raise KeyError('Given Vertex is not part of the Graph')
q.enqueue(start)
while not q.is_empty():
vertex = q.dequeue()
output.add(vertex)
for neighbor in self.get_neighbors(vertex):
if neighbor['vertex'] not in output:
q.enqueue(neighbor['vertex'])
return output
def test_queue_enqueue():
value = 1
queue = Queue()
queue.enqueue(value)
expected = value
actual = queue.front.value
assert actual == expected
def test_enqueue_two():
q = Queue()
q.enqueue("apples")
q.enqueue("bananas")
actual = q.peek()
expected = "apples"
assert actual == expected
def test_can_peek_queue():
queue = Queue()
queue.enqueue(1)
queue.enqueue(2)
actual = queue.peek()
expected = 1
assert actual == expected
def test_queue_dequeue():
value = 1
queue = Queue()
queue.enqueue(value)
actual = queue.dequeue()
expected = value
assert actual == expected
def test_enqueue_multiple():
queue = Queue()
queue.enqueue(3)
queue.enqueue(2)
queue.enqueue(1)
actual = queue.rear.value
expected = 1
assert actual == expected
def test_peek():
q = Queue()
q.enqueue("apple")
q.enqueue("banana")
q.enqueue("cucumber")
actual = q.peek()
expected = "apple"
assert actual == expected
def test_can_empty_queue():
queue = Queue()
queue.enqueue(1)
queue.enqueue(1)
queue.dequeue()
queue.dequeue()
actual = queue.is_empty()
expected = True
assert actual == expected
def test_queue_enqueue_many():
value1 = 1
value2 = 2
queue = Queue()
queue.enqueue(value1)
queue.enqueue(value2)
expected = value1
actual = queue.front.value
assert actual == expected
def test_queue_dequeue_until_empty():
value1 = 1
value2 = 2
queue = Queue()
queue.enqueue(value1)
queue.enqueue(value2)
queue.dequeue()
queue.dequeue()
actual = queue.front
expected = None
assert actual == expected
def test_exhausted():
# TODO TODO is empty should return true after dequeueing all previously queued items
q = Queue()
q.enqueue('apples')
q.enqueue('oranges')
q.dequeue()
q.dequeue()
actual = q.is_empty()
expected = True
assert actual == expected
def test_peek_post_dequeue():
# TODO it should return a new first value if peek is called after a dequeue
q = Queue()
q.enqueue('apples')
q.enqueue('oranges')
actual = q.peek()
expected = 'apples'
assert actual == expected
q.dequeue()
actual = q.peek()
expected = 'oranges'
assert actual == expected
def breadth_first(self, vertex):
node = []
breadth = Queue()
breadth.enqueue(vertex)
visited = set()
while not breadth.is_empty():
front = breadth.dequeue()
node.append(front.value)
for neighbor in self.get_neighbor(front):
if neighbor.vertex.value not in visited:
visited.add(neighbor.vertex.value)
breadth.enqueue(neighbor.vertex)
return node
def breadth_first(self) -> list:
"""Traverse the tree in breadth-first manner
Returns:
list: Values of the tree
"""
output = []
if self.root:
q = Queue()
q.enqueue(self.root)
while not q.is_empty():
el = q.dequeue()
output.append(el.val)
if el.left:
q.enqueue(el.left)
if el.right:
q.enqueue(el.right)
return output
def tree_intersection(bt1: object, bt2: object) -> set:
output = set()
q1 = q2 = Queue()
if bt1.root and bt2.root:
q1.enqueue(bt1.root)
q2.enqueue(bt2.root)
while not (q1.is_empty() and q2.is_empty()):
el1, el2 = q1.dequeue(), q2.dequeue()
if el1.val == el2.val:
output.add(el1.val)
if el1.left and el2.left:
q1.enqueue(el1.left)
q2.enqueue(el2.left)
if el1.right and el2.right:
q1.enqueue(el1.right)
q2.enqueue(el2.right)
return output
def test_multiple_enqueue_fails():
queue = Queue()
queue.enqueue(3)
queue.enqueue(2)
queue.enqueue(1)
assert queue.rear.value != 2
def test_is_empty():
# TODO is empty should return true if no items were enqueued
q = Queue()
actual = q.is_empty()
expected = True
assert actual == expected
def test_queue_peek_empty_exception():
queue = Queue()
with pytest.raises(Exception):
queue.peek()
def test_enqueue():
q = Queue()
q.enqueue("apple")
actual = q.front.value
expected = "apple"
assert actual == expected
def test_instantiate_queue():
queue = Queue()
assert queue.front == None
def test_enqueue_into_queue():
queue = Queue()
queue.enqueue(1)
actual = queue.rear.value
expected = 1
assert actual == expected
def __init__(self):
self.cats = Queue()
self.dogs = Queue()
self.animal_order = Queue()
def test_raise_exception_empty_queue():
queue = Queue()
with pytest.raises(InvalidOperationError) as e:
queue.peek()
assert str(e.value) == "Peeking from an empty queue!"