A Queue is a linear structure which follows a particular order in which the operations are performed. The order is First In First Out (FIFO). A good example of a queue is any queue of consumers for a resource where the consumer that came first is served first. The difference between stacks and queues is in removing. In a queue, we remove the item that was least recently added.
Characteristics
- FIFO (First In First Out)
- Think “Customers in a line”
Applications
- CPU Scheduling
- Disk Scheduling
- IO Buffers
- Pipes
- File IO
Structure
queue.isEmptyReturns a Bool with true if the queue is empty or false if the queue has elements.
queue.countReturns an Int with the number of elements in the queue.
queue.enqueue(_ element: Element)Adds the given element to the back of the queue.
queue.dequeue() -> SinglyLinkedListNode?Removes the node from the front of the queue and returns the node.
queue.peek() -> SinglyLinkedListNode?Returns the node from the front of the queue.
Queue with Linked List Implementation
Code
