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发帖数: 11 | 1 f(n+1)-2
where f(n) is number of blocks that n cut 3 dimension space.
consider: (1) first cut the whole ring to 2 half ring. (cut surface is 2
circles).
(2) make n cuts, make sure that n cuts do not intersect the first
cut in those 2 circles, and the intersection points among these n cuts are all
in the ring. (n+1) cuts in total, so it is f(n+1) blocks now.
(3) the first cut only results in 2 more blocks. So it will be
f(n+1)-2 without the first cut. |
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