Overview
Topological sort DAG (Directed Acyclic Graph) ke nodes ko dependencies ke hisaab se order karta hai.
Analogy
Jaise courses ka order determine karna—pehle prerequisites complete karo.
Step-by-step
- Har node ka in-degree calculate karo
- Saare in-degree=0 nodes queue mein add karo
- Node dequeue karo, neighbors ka in-degree -1 karo
- In-degree 0 hone par queue mein add karo, agar saare process nahi hue toh cycle hai
Visual
1→2→4
↓
3→4
Topo: [1,2,3,4]
Common mistakes
- Sirf directed graphs ke liye use ho sakta hai
- Cycle detection nahi karna
Practice questions
- Dependencies list se valid course schedule banao
- Kahn's algorithm aur DFS course scheduling mein compare karo