求救!咋样,可以成攻救人?

求救!咋样,可以成攻救人?

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4 people need to cross a bridge before it collapese,  they have seventeen minutues befor the collapse. there is only one flashlight and each must have the light to cross. the bridge can only hold 2 people at a time ,can you save them ?


1. 1 old man (need 10 minute to cross)


2. 40  year old woman (need 5 minute to cross)


3. 20 year old (need 2 minute to cross)

所有跟帖: 

回复:求救!咋样,可以成攻救人? -guest007- 给 guest007 发送悄悄话 (69 bytes) () 09/28/2010 postreply 18:06:11

回复:回复:求救!咋样,可以成攻救人? -piffle- 给 piffle 发送悄悄话 (658 bytes) () 09/29/2010 postreply 12:31:33

Another solution: switching P1 and P2 also works -newers- 给 newers 发送悄悄话 newers 的博客首页 (0 bytes) () 10/03/2010 postreply 07:32:54

1. old + yong (10), 2. Young back(2) 3. Two go (5) -mimiwiwi- 给 mimiwiwi 发送悄悄话 (0 bytes) () 09/30/2010 postreply 02:00:10

17 minutes is up, you still have 1 person left behind -oops_yz- 给 oops_yz 发送悄悄话 (0 bytes) () 10/01/2010 postreply 09:19:53

回复:求救!咋样,可以成攻救人? -m6412- 给 m6412 发送悄悄话 (164 bytes) () 10/04/2010 postreply 18:38:54

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