Queue Class
Your task is to create a
Queue
class in Python that uses a list as its internal data structure. This class should provide the following methods:enqueue()
: This method takes an input element and adds it to the end of the queue.
dequeue()
: This method removes an element from the front of the queue and returns it.
size()
: This method returns the current number of elements in the queue.
Please adhere to the following specifications:
- The queue should be implemented using a list. This means that the list should not be directly accessible from outside the class.
- The
enqueue
method should take one parameter, the element to be added to the queue. It should not return anything.
- The
dequeue
method should not take any parameters. It should return the element that was removed from the queue. If the queue is empty whendequeue
is called, it should returnNone
.
- The
size
method should not take any parameters. It should return an integer representing the number of elements currently in the queue.
Input | Output |
q = Queue(); q.enqueue('a'); q.enqueue('b'); print(q.size()); print(q.dequeue()); print(q.dequeue()); print(q.dequeue()) | 2
a
b
None |
Constraints
Time limit: 2 seconds
Memory limit: 512 MB
Output limit: 1 MB