題目是
There are eight people, denoted A,B,....,H be seated about the square table,
and two of the eight people, say A and B, do not get along well, how many
different seatings are possible with A and B not sitting next to each other ?
課本的答案是：
8!/4 - (2*6! + 2*6!) = 7200 ; 坐在同一側跟坐在桌腳兩側都算進去了
可是我想法是：
8!/4 - (6!/2 + 6!/2) = 9360 ; 因為是方桌所以我都除以四
請問是我的想法錯還是課本解答錯？
麻煩可以幫我解惑一下嗎...
感激不盡
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