Nice one about max-flow :) solvable at O(N*log(N)) by greedy propagation of most backward vertex using any of still unused elevators (did it using the farthest one, but it doesn't matter)

Edited by author 01.07.2026 22:02

Hi!

I believe test #3 is invalid - there is no way to get from floor 1 to floor N.

Can you please check?

Thank you!