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标题: Uncover the Numbers (Logic) --ZT from WXC [打印本页]

作者: 野菜花 时间: 2005-11-9 04:11
标题: Uncover the Numbers (Logic) --ZT from WXC

By commentate

Arthur and Bert each writes down a positive integer on a piece of paper and then shows it to Charles. Charles then writes two numbers on a blackboard, visible to Arthur and Bert: one of them is the sum of Arthur's and Bert's numbers, and the other is a random number.
After this Charles asks Arthur if he knows Bert's number. If Arthur says he doesn't know, then he asks Bert if he knows Arthur's number. If Bert says he doesn't know, Charles continues with Arthur, then if necessary with Bert and so on... until he gets a positive answer.

When will Charles get a positive answer?

作者: husonghu 时间: 2005-11-9 04:29
标题: 谢谢菜花ZT好题[@};-][@};-] 也感谢原贴者commentate[@};-][@};-]

谢谢菜花ZT好题

也感谢原贴者commentate

作者: QL 时间: 2005-11-9 16:02
标题: 回复：Uncover the Numbers (Logic) --ZT from WXC

I haven't count very carefully yet, but it seems to be at most [min(a,b)/(2*|a-b|)]+1, where a,b are the two numbers shown on the board.

作者: 野菜花 时间: 2005-11-9 18:04
标题: 回复：回复：Uncover the Numbers (Logic) --ZT from WXC

It is not exactly same as mine, but similar. Could you explain your logic?

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