Intermediate Topic 27 of 52 Data Structures
Graphs
Vertices connected by edges modeling relationships.
How it works
A graph has vertices and edges (directed or undirected, weighted or not). It models relationships such as roads, friendships or dependencies and is the subject of many algorithms.
Where it is used
Maps, social networks, build systems, the web.
Common pitfall
Choosing the wrong representation, and forgetting to track visited nodes in cycles.
Where it fits in the course
Graphs is topic 27 of 52 in Data Structures, rated Intermediate. It follows Fenwick Trees. The next topic is Adjacency List.
Practice and explore
- Open the interactive lesson, with a mini quiz.
- Take the Data Structures quiz.
- Explore the Graph Traversal visualizer: BFS, DFS and Dijkstra on a weighted graph.
How to study this topic
- Read the explanation above and restate the definition in your own words.
- Open the interactive lesson and answer its mini quiz.
- Read the common pitfall, then write a short example that avoids it.
- Check your understanding in the Data Structures quiz, and revisit the topic if you miss a question.
Frequently asked questions
What is Graphs?
Vertices connected by edges modeling relationships. It belongs to Data Structures and is an intermediate-level topic.
Where do people use Graphs?
Maps, social networks, build systems, the web.
What is the most common mistake with Graphs?
Choosing the wrong representation, and forgetting to track visited nodes in cycles.
What should I learn before this topic?
Start with Fenwick Trees, 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 Graph Traversal in the Visual Lab.
Is Graphs hard to learn?
It is an Intermediate topic. Be comfortable with the Beginner topics in this area first, then read the common pitfall carefully, since it is where most mistakes happen.
How long does it take to learn Graphs?
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 Graphs?
Fenwick Trees, Adjacency List, Segment Trees are closely connected. The full list is in the related topics section of this page.
What should I study after Graphs?
Continue with Adjacency List, the next topic in Data Structures.
Related topics
- Fenwick Trees (Data Structures)
- Adjacency List (Data Structures)
- Segment Trees (Data Structures)
- Adjacency Matrix (Data Structures)
- Functions and Graphs (Math for Computing)
- Control Flow Graphs (Languages & Compilers)
- Knowledge Graphs (Emerging & Frontier Topics)