Mr. Goldstein: Created page with "=== 4.1.1.4 Queues: First In, First Out (FIFO) === Now, imagine a line of people waiting for a roller coaster. The first person who gets in line is the first person to get on the ride. A '''queue''' in computer science is just like that! It follows a rule called '''FIFO''', which stands for '''First In, First Out'''. The first item you put ''in'' the queue is always the first item to come ''out''. * '''Adding items to a queue is called "enqueuing."''' (Like joining the..."

2025-07-09T14:37:10Z

Created page with "=== 4.1.1.4 Queues: First In, First Out (FIFO) === Now, imagine a line of people waiting for a roller coaster. The first person who gets in line is the first person to get on the ride. A '''queue''' in computer science is just like that! It follows a rule called '''FIFO''', which stands for '''First In, First Out'''. The first item you put ''in'' the queue is always the first item to come ''out''. * '''Adding items to a queue is called "enqueuing."''' (Like joining the..."

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=== 4.1.1.4 Queues: First In, First Out (FIFO) ===
Now, imagine a line of people waiting for a roller coaster. The first person who gets in line is the first person to get on the ride. A '''queue''' in computer science is just like that!

It follows a rule called '''FIFO''', which stands for '''First In, First Out'''. The first item you put ''in'' the queue is always the first item to come ''out''.

* '''Adding items to a queue is called "enqueuing."''' (Like joining the end of the line)
* '''Removing items from a queue is called "dequeuing."''' (Like the person at the front of the line getting on the ride)
* '''Examples of Queues in real life:'''
** A printer queue: The first document sent to the printer is the first one that gets printed.
** Customer service lines: The first caller in line is the first one to be helped.

==== Priority Queues ====
Sometimes, in a line, certain people get to go first, even if they weren't first in line. Think of an emergency room at a hospital: the most urgent cases are seen first, regardless of when they arrived. This is like a '''priority queue'''.

In a priority queue, each item has a "priority" level. Items with higher priority get to come out of the queue ''before'' items with lower priority, even if the lower-priority items arrived first. If two items have the same priority, then the FIFO rule (first in, first out) usually applies to them.

* '''Example:''' A hospital emergency room, or tasks in a computer's operating system where some tasks are more important than others.

==== Bibliography for Queues ====

* '''Kiddle:''' [https://kids.kiddle.co/Stack_(data_structure) Data structure Facts for Kids]
* '''High Speed Training:''' [https://www.highspeedtraining.co.uk/hub/fifo-food-storage/ Using a FIFO Food Storage System] | Guidance & Free Checklist
* '''State Food Safety:''' [https://www.statefoodsafety.com/Resources/Resources/april-cartoon-first-in-first-out-fifo April Cartoon: First In, First Out (FIFO)]
* '''LMU Computer Science:''' [https://cs.lmu.edu/~ray/notes/pqueues/ Priority Queues]
* '''GeeksforGeeks:''' [https://www.geeksforgeeks.org/dsa/priority-queue-set-1-introduction/ Introduction to Priority Queue]

4.1.1.4 Queues (FIFO, Priority Queues) - Revision history