LearnViz CompSci
Home / Learn / Data Structures / Priority Queue

Beginner Topic 9 of 52 Data Structures

Priority Queue

Collection always yielding the element with highest priority first.

How it works

A priority queue always removes the highest- (or lowest-) priority element next, typically via a binary heap: insert and extract are O(log n), peek is O(1).

Where it is used

Dijkstra, event simulation, OS schedulers, top-k problems.

Common pitfall

Equal priorities are not necessarily served FIFO unless you add a tie-breaker.

Where it fits in the course

Priority Queue is topic 9 of 52 in Data Structures, rated Beginner. It follows Deque. The next topic is Hash Tables.

Practice and explore

How to study this topic

  1. Read the explanation above and restate the definition in your own words.
  2. Open the interactive lesson and answer its mini quiz.
  3. Read the common pitfall, then write a short example that avoids it.
  4. Check your understanding in the Data Structures quiz, and revisit the topic if you miss a question.

Frequently asked questions

What is Priority Queue?
Collection always yielding the element with highest priority first. It belongs to Data Structures and is a beginner-level topic.
Where do people use Priority Queue?
Dijkstra, event simulation, OS schedulers, top-k problems.
What is the most common mistake with Priority Queue?
Equal priorities are not necessarily served FIFO unless you add a tie-breaker.
What should I learn before this topic?
Start with Deque, the topic just before it in Data Structures.
How can I practice it?
Answer the mini quiz in the interactive lesson, then take the Data Structures quiz. You can also explore Stack, Queue & Linked List in the Visual Lab.
Is Priority Queue hard to learn?
It is a Beginner topic, so it works as an entry point. If the terms are new, read the explanation twice and try the visualizer before the quiz.
How long does it take to learn Priority Queue?
Most learners can read the explanation and finish the interactive lesson in under an hour. Fluency comes from applying the idea, so plan a few short practice sessions with the quiz.
Which topics are related to Priority Queue?
Deque, Hash Tables, Queues are closely connected. The full list is in the related topics section of this page.
What should I study after Priority Queue?
Continue with Hash Tables, the next topic in Data Structures.

Related topics