PuzzleUp 2010 (2) Round Table - 拼圖

首頁：http://www.puzzleup.com/2010/
時限：2010/07/21（四）19:00～07/27（三）18:59

答案可上傳５次，但每改１次扣２０分（基本分為１００分）
在比賽期間內可隨時回答，但只有在時限內回答者有額外加分

◆Round Table

A group of people is sitting around a round table. They give a coffee break.

When they return to the table after the break, they sit down randomly.

Interestingly, they notice that the six closest persons sitting

next to each one of them (three to the left, and three to the right)

are completely different from the six closest persons in the previous setting.

At least how many persons should be there?


有一群人圍著一圓桌而坐.接著他們離開去喝點咖啡休息一下,當他們回到圓桌後隨機坐下.

很有趣的,他們每個人都發現: 最靠近自己的六個人(左邊三個右邊三個)

和喝咖啡前最靠近自己的六個人 都不一樣


那麼,這群人至少有幾個才有可能發生這種情形?



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這題要問的應該跟上一題相反

上一題是要有幾個三角形才能保證在任何情況下都成立(cover all cases)
這題是要有幾個人 才有可能成立(特例)
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