data_structures.queues.circular_queue

Classes

CircularQueue

Circular FIFO queue with a fixed capacity

Module Contents

class data_structures.queues.circular_queue.CircularQueue(n: int)

Circular FIFO queue with a fixed capacity

__len__() → int

>>> cq = CircularQueue(5)
>>> len(cq)
0
>>> cq.enqueue("A")
<data_structures.queues.circular_queue.CircularQueue object at ...>
>>> cq.array
['A', None, None, None, None]
>>> len(cq)
1

dequeue()

This function removes an element from the queue using on self.front value as an index and returns it

>>> cq = CircularQueue(5)
>>> cq.dequeue()
Traceback (most recent call last):
   ...
Exception: UNDERFLOW
>>> cq.enqueue("A").enqueue("B").dequeue()
'A'
>>> (cq.size, cq.first())
(1, 'B')
>>> cq.dequeue()
'B'
>>> cq.dequeue()
Traceback (most recent call last):
   ...
Exception: UNDERFLOW

enqueue(data)

This function inserts an element at the end of the queue using self.rear value as an index.

>>> cq = CircularQueue(5)
>>> cq.enqueue("A")
<data_structures.queues.circular_queue.CircularQueue object at ...>
>>> (cq.size, cq.first())
(1, 'A')
>>> cq.enqueue("B")
<data_structures.queues.circular_queue.CircularQueue object at ...>
>>> cq.array
['A', 'B', None, None, None]
>>> (cq.size, cq.first())
(2, 'A')
>>> cq.enqueue("C").enqueue("D").enqueue("E")
<data_structures.queues.circular_queue.CircularQueue object at ...>
>>> cq.enqueue("F")
Traceback (most recent call last):
   ...
Exception: QUEUE IS FULL

first()

Returns the first element of the queue >>> cq = CircularQueue(5) >>> cq.first() False >>> cq.enqueue(“A”).first() ‘A’

is_empty() → bool

Checks whether the queue is empty or not >>> cq = CircularQueue(5) >>> cq.is_empty() True >>> cq.enqueue(“A”).is_empty() False

array

front = 0

n

rear = 0

size = 0