1. Data Structures - Queues

2. Introducing the Queue FIFO ~ First In First Out
How does a queue (line) work?
First person gets in line
Second person gets in line after first person
etc.
The first person to get out of the line is the first person in line
enqueue – data is added to the end (tail) of the queue
dequeue – data is removed from the beginning (head) of the queue
isEmpty – returns True if queue is empty

3. Queue Example ENQUEUE D ENQUEUE E
ENQUEUE A #What is at the head of the line? and the tail?
DEQUEUE
DEQUEUE #What is at the head of the line? and the tail?

4. Why do we use queues?
Used to ensure the first-come-first-serve concept
The first things added are the first things to be removed
Where do we see queues in real life?
Where do you think we see queues in technology?

5. Queue Implementation How do we implement a queue?
class
Static size vs. Dynamic size
Let’s draw a queue...
Try out some queue operations (enqueue, dequeue, etc.)
What pieces of information do we need to track?