An undirected graph is complete if there is an edge

An undirected graph is complete if there is an edge between every pair of vertices. Given a complete undirected graph on n vertices, in how many ways can you choose a direction for the edges so that there are no directed cycles?

(A) n
(B) n!
(C) n(n-1)/2
(D) 2n(n-1)/2

Answer: B
 

1Comment
Sumit Verma sumitverma 10 Jan 2018 09:34 pm