Hi!

Hints

A: Tag: Greedy!

B: Tag: Greedy!

C: For each vertex like v find ex_v, the expected length of their journey if they start from v.

D: Tag: Inclusion exclusion.

E: Find the maximum clique.

Solutions

Arpa's solution: 29412123.

Arpa's solution: 29412154.

Arpa's solution: 29412220.

NikaraBika's solution: 29458745.

Arpa's solution: 29412249.

P.S. Please notify me if there is any problem.