A cube with size 10 * 10 * 10 consists of 1000 unit cubes, all colored white. A and B play a game on this cube. A chooses some pillars with size 1 * 10 * 10 such that no two pillars share a vertex or side, and turns all chosen unit cubes to black. B is allowed to choose some unit cubes and ask A their colors. How many unit cubes, at least, that B need to choose so that for any answer from A, B can always determine the black unit cubes?
(In reply to
smoke clears by Steven Lord)
True, but A is not bound to choose a single pillar. He can choose 'some'.
Assume that 2 blacks are disclosed by the initial 9 selections.
Then an additional selection is still needed to check whether there is in fact a third 'pillar', meaning that 13 selections are still required
Edited on July 31, 2021, 2:08 am
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Posted by broll
on 2021-07-31 02:00:46 |
re: smoke clears
