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Advanced Topic 39 of 51 Algorithms

Kruskal's Algorithm

MST built by adding lightest edges avoiding cycles.

How it works

Sort edges by weight and add each one unless it creates a cycle, checked with disjoint-set union. O(E log E).

Where it is used

Sparse graphs, clustering.

Common pitfall

Forgetting to use union-find makes cycle checks slow.

Where it fits in the course

Kruskal's Algorithm is topic 39 of 51 in Algorithms, rated Advanced. It follows Minimum Spanning Tree. The next topic is Prim's Algorithm.

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 Algorithms quiz, and revisit the topic if you miss a question.

Frequently asked questions

What is Kruskal's Algorithm?
MST built by adding lightest edges avoiding cycles. It belongs to Algorithms and is an advanced-level topic.
Where do people use Kruskal's Algorithm?
Sparse graphs, clustering.
What is the most common mistake with Kruskal's Algorithm?
Forgetting to use union-find makes cycle checks slow.
What should I learn before this topic?
Start with Minimum Spanning Tree, the topic just before it in Algorithms.
How can I practice it?
Answer the mini quiz in the interactive lesson, then take the Algorithms quiz.
Is Kruskal's Algorithm hard to learn?
It is an Advanced topic. Expect to read the explanation more than once and to connect it with earlier topics. Working through a small example by hand helps most.
How long does it take to learn Kruskal's Algorithm?
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 Kruskal's Algorithm?
Minimum Spanning Tree, Prim's Algorithm, A* Search are closely connected. The full list is in the related topics section of this page.
What should I study after Kruskal's Algorithm?
Continue with Prim's Algorithm, the next topic in Algorithms.

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