Approach Summary
Kahn's BFS. Process level by level (each level = one semester). Return number of levels if all nodes processed, else -1 (cycle).
How to Recognize This Pattern
- "Minimum semesters to complete all courses given prerequisites"
- Topological BFS counting levels = parallel rounds
Complexity Analysis
Time Complexity
O(V + E)
Space Complexity
O(V + E)
Tags
Graph Topological Sort BFS