think easy - combinatorial solution 回複:誰能用圖論來解這道題? 懇請牛人出著。
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mathg
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2010-08-15 21:46:19
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72.
First permute 135 = 3!. For each permutation, place 6 and avoid adjacent with 3 = 2, then place 24=c(2,3)*2!=6 So tatol = 6*2*6 = 72