We invite you to participate in CodeChef’s Starters 241, this Wednesday, 3rd June, rated for 5 stars (i.e. for users with rating < 2200).

Time: 8:00 PM — 10:00 PM IST

Joining us on the problem setting panel are:

• Contest Admin: Shreyan Dominater069 Ray

• Setter: Sushil SmolBrain Raaja and Shreyan Dominater069 Ray

• Tester and Statement Verifier: Sushil SmolBrain Raaja

• Text Editorialist: Nishank IceKnight1093 Suresh

Written editorials will be available for all on discuss.codechef.com. Pro users can find the editorials directly on the problem pages after the contest. The video editorials of the problems will be available only to Pro users.

Also, if you have some original and engaging problem ideas, and you’re interested in them being used in CodeChef's contests, you can share them here. Hope to see you participating.

Good Luck!

Problem Link

Abridged problem statement: Count the total number of distinct topological orderings of a DAG (Directed Acyclic Graph), given that each node has at most 1 incoming edge

My approach: Find an arbitrary topological ordering of the DAG using dfs and use dp to find the answer. However, I'm unable to formulate the dp states correctly.

I've hunted the entire internet for this problem's solution, but couldn't find it, so the CF community is my only hope! Please provide some hints to solve this problem.

Thanks :D