  We consider the problem of computing the optimal meeting point of a set of N
crab submarines. First, we analyze the case where the submarines are allowed
any position on the real line: we provide a constructive proof of optimality
and we use it to provide a linear-time algorithm to find the optimal meeting
point for the case of sorted starting points. Second, we use the results for
the continuous case to solve the case where the crab submarines are restricted
to integer locations: we show that, given the solution of the corresponding
continuous problem, we can find the optimal integer solution in linear time.
