What is the Course Schedule pattern?

The Course Schedule is a common coding interview pattern in Graphs problems. It provides a structured approach to solving related algorithm challenges efficiently.

When should I use Course Schedule?

Use the Course Schedule pattern when you encounter problems matching its characteristics. Check the "When to Use" and "Clues" sections in the lesson for specific indicators.

Is Course Schedule asked in FAANG interviews?

Yes, Course Schedule is an essential pattern commonly tested in FAANG and top tech company technical interviews.

Graphs (Topological Sort)

Medium

Course Schedule

Determine if it is possible to finish all courses given prerequisites.

10 min read

Solve on LeetCode

Problem Understanding

There are numCourses courses labeled 0 to numCourses - 1. You are given prerequisites array where [a, b] means taking course b is mandatory before a.

Return true if you can finish all courses, false otherwise (i.e., if there is a cycle).

Strategy (Kahn's Algorithm)

This is a Cycle Detection problem in a Directed Graph.

Build Adjacency List and In-Degree array.
Push all nodes with in-degree == 0 to Queue.
Process Queue, decrementing neighbor in-degrees.
Count how many nodes we processed.
If processed_count == numCourses, return true.

Interactive Visualization

Step 1 / 1

Visualization coming soon...

Initializing...

Custom Input

See the Logic in Motion

Stop memorizing code. Unlock the full interactive visualizer to master the logic step-by-step.

Unlock VisualizerPREMIUM FEATURE

Stop Guessing, Start Mastering.

Build the FAANG intuition. Master this pattern with optimized implementations, visual dry runs, and our curated collection of high-yield problems.

Start Your Premium Prep