LearnViz CompSci
Home / Learn / Data Structures / Open Addressing

Beginner Topic 13 of 52 Data Structures

Open Addressing

Collision strategy probing other slots in the table itself.

How it works

In open addressing every entry lives directly in the table array, and a collision is resolved by probing for another empty slot using a deterministic sequence such as linear probing, quadratic probing or double hashing. Lookup follows the same probe sequence until it finds the key or an empty slot. It has excellent cache behavior and no per-node allocation, but performance drops sharply as the table fills.

Where it is used

Python dictionaries, many high-performance hash maps and embedded systems with tight memory use open addressing. Linear probing is especially fast for small keys.

Common pitfall

Deletion cannot simply empty a slot, because that breaks probe chains; use tombstone markers. Primary clustering slows linear probing, and the table must resize well before it is full, typically at about 70 percent load.

Where it fits in the course

Open Addressing is topic 13 of 52 in Data Structures, rated Beginner. It follows Chaining. The next topic is Trees.

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 Open Addressing?
Collision strategy probing other slots in the table itself. It belongs to Data Structures and is a beginner-level topic.
Where do people use Open Addressing?
Python dictionaries, many high-performance hash maps and embedded systems with tight memory use open addressing.
What is the most common mistake with Open Addressing?
Deletion cannot simply empty a slot, because that breaks probe chains; use tombstone markers.
What should I learn before this topic?
Start with Chaining, 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 Hash Table in the Visual Lab.
Is Open Addressing 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 Open Addressing?
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 Open Addressing?
Chaining, Trees, Hash Collisions are closely connected. The full list is in the related topics section of this page.
What should I study after Open Addressing?
Continue with Trees, the next topic in Data Structures.

Related topics