Fred Lunnon wrote:
I may have misunderstood something here --- as stated, the answer seems easily to be n --- even if the velocity b _is_ known to the player.
If the velocity is known, then I completely agree that you can do it in n shots, and no fewer. There are n possibilities for the sub's trajectory, and they never overlap, so each shot can only take out one. In the actual problem, the answer is *larger* than n. There are n^2 possible trajectories, and you certainly hit n of them with your first shot. But you can only hit n-1 with your second: no matter what first pair of shots you take, there's exactly one sub trajectory that you would have hit with *both* of them, so the union only nets 2n-1 of the n^2 possibilities. --Michael Kleber -- It is very dark and after 2000. If you continue you are likely to be eaten by a bleen.