Agree

來源: 屋漏痕 於 2009-07-20 05:09:52 [] [博客] [舊帖] [給我悄悄話] 閱讀數 : (527 bytes)
回答: 2^(2n-2) * 6 由 屋漏痕 於 2009-07-16 10:15:15

If a row (or column) is fixed and on this row there exist two adjacent squares that have the same color, then the whole board is fixed. There are 2^n-2 such cases.

The only two cases that are not covered are:
black, white, black, white, bwbwbw...;
or white, black, white, black, wbwb...

For these two cases, their adjacent row (or column) must be
black, white, black, white, bwbwbw...;
or white, black, white, black, wbwb...

So there are 2^n such cases.

And the total is 2^(n+1)-2.

請您先登陸，再發跟帖！