>

For each request, you must find the minimal
  (I mean, with minimal y*width+x) element in a two-dimensial array,
which has the following property:
  1. There was a period, when it wasn't visited for at
     least 1000 days. (sorry about my english...)
     I think, it writes as: some_request_time-last_visited>=1001
     ( at least one such request must exist )

  2. All it's eight neighbours weren't visited for at least 100 days.
     current_request_time-last_neighbours_visited>=101

Well, anyways I found that their input has something-that-I-can't-
imagine, because my algorithm wouldn't work so much time in the
worst-case.