wu :: forums - Print Page


    
      
        wu :: forums
        (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi)
      

        riddles >> medium >> fork in the road variation
        
(Message started by: riddler358 on May 6^th, 2016, 10:38am)

Title: fork in the road variation
Post by riddler358 on May 6^th, 2016, 10:38am

At a fork in the road between two cities, safe city and cannibal city, you see 2 people. One is very wise and always tells the truth, and other person is sneaky and can tell truth or lie, is very smart and have sole intention of tricking you into choosing wrong path. You can ask any number of questions to any one of them or to both of them. What approach you suggest?

Title: Re: fork in the road variation
Post by towr on May 6^th, 2016, 12:14pm

[hide]I don't think there is a solution. The sneak will just answer any question the way the wise man would if the two cities were swapped. There is no way to distinguish those two possible situations.[/hide]

Title: Re: fork in the road variation
Post by riddler358 on May 6^th, 2016, 10:35pm

i have few ideas how to approach this problem, maybe none of them works, but i would love to see some ideas of others

Title: Re: fork in the road variation
Post by towr on May 6^th, 2016, 11:50pm

[hide]Well, unless anyone's ideas work when you replace the sneak by a copy of the wise man from an alternate universe where the position of the two worlds is reversed, you'll be out of luck.
It's a perfectly symmetrical problem.[/hide]

Title: Re: fork in the road variation
Post by riddler358 on May 7^th, 2016, 12:47am

[hide]how about asking them for solution?[/hide]

[hide]how about asking one guy and then lie to other one about previous answer?[/hide]

[hide]how about asking question: which way is right? (dual meaning of right)?[/hide]

[hide]how about asking them to duel at chess or some other games whereas wise guy should win without cheating?[/hide]

[hide]how about asking: what is my favourite colour?[/hide]

Title: Re: fork in the road variation
Post by rmsgrey on May 7^th, 2016, 9:10am

I'm with towr on this one - if the sneaky person is smart enough to know exactly what the wise person would say if the paths were switched, they can always fool you.

Title: Re: fork in the road variation
Post by riddler358 on May 8^th, 2016, 1:38am

but can he predict every answer of wise man right away? are only questions allowed with straightforward yes or no answer?

Title: Re: fork in the road variation
Post by rmsgrey on May 8^th, 2016, 6:14am

on 05/08/16 at 01:38:47, riddler358 wrote:

but can he predict every answer of wise man right away? are only questions allowed with straightforward yes or no answer?

The wise person has to be able to decide what he's going to say - the sneaky person only needs to be able to carry out the same process at least as quickly.

Title: Re: fork in the road variation
Post by riddler358 on May 8^th, 2016, 2:58pm

what about topics for which opinion can change?

Title: Re: fork in the road variation
Post by dudiobugtron on May 8^th, 2016, 7:54pm

Just ignore them and plot the path to Safe City using your GPS or google maps.

Title: Re: fork in the road variation
Post by riddler358 on May 8^th, 2016, 11:52pm

you don't know which one of these guys controls GSP and google maps

Title: Re: fork in the road variation
Post by rmsgrey on May 9^th, 2016, 7:47am

on 05/08/16 at 14:58:07, riddler358 wrote:

what about topics for which opinion can change?

What about them? The sneaky person doesn't even need to perfectly mimic the wise person's responses - they just need to do well enough that you can't tell which is the genuine wise person, and which is the faker...

Title: Re: fork in the road variation
Post by riddler358 on May 9^th, 2016, 1:38pm

on 05/09/16 at 07:47:36, rmsgrey wrote:

but any difference gives you clues

imagine asking them to paint something or sing a song

Title: Re: fork in the road variation
Post by towr on May 9^th, 2016, 11:03pm

on 05/09/16 at 13:38:20, riddler358 wrote:

imagine asking them to paint something or sing a song

What sort of song does a wise man compose? What sort of painting does a wise man paint?
And if you can figure that out, why wouldn't the sneak be able to?

Unless you can think of something definite, something testable, that the wise man can do which the sneak can't, then you won't be able to tell them apart with any certainty.

Also consider this, suppose you ask them for the answer to the 100 REM puzzle, and the wise-man gives the correct, but hardly intuitive, answer; and the sneak gives an intuitive, believable (but wrong) answer, then which path do you take? :P
The sneak has the easier task, because he only needs to convince you. The wise man needs to convince you with the truth. And if politics has taught us anything, it's that people are easily (and often more easily) convinced by things other than the truth.

The fact that the sneak could in theory emulate the wise man from a universe where the two cities are swapped means there is no solution. And the fact he isn't constrained by the truth while trying to convince you means you're totally screwed.

Title: Re: fork in the road variation
Post by riddler358 on May 9^th, 2016, 11:30pm

i never said you can be sure, sneak cant predict what song wise man will sing and vice versa, i have a feeling that wise man would be better in creating and sneak in copying

you might also try to make sneak angry, ask them "is sneaky one ->insult here<-?", if they both say yes keep em coming, sneaky must copy each answer except valid road answer to fool you, make him sweat for it and make him angry, give him a chance to make mistake

Title: Re: fork in the road variation
Post by riddler358 on May 10^th, 2016, 8:00am

BE CAREFUL HERE!
POSSIBLE ANSWER IS HIDDEN BELOW!
[hide]i would ask if they can go to city of safety for the night and come back next morning.[/hide]

Title: Re: fork in the road variation
Post by towr on May 10^th, 2016, 9:00am

I was kind of assuming [hide]the sneak was a cannibal, and therefore perfectly willing to walk you to the cannibal city if need be.[/hide]
But if [hide]he's not, and the cannibals would eat him, and he prefers living more than seeing you die, and getting him to do something other than just answering question is valid solution,[/hide] then I agree that's an option.

Title: Re: fork in the road variation
Post by riddler358 on May 10^th, 2016, 11:25am

even if [hide]he was a cannibal, what would they eat if no new wanderers are brought to the city?[/hide]

just had a thought [hide]maybe city of cannibals is empty like room of hungry lions that haven't eaten in 3 years :D[/hide]

Title: Re: fork in the road variation
Post by rmsgrey on May 10^th, 2016, 12:35pm

I've always liked the suggestion for dealing with an artistic liar of "Did you know they're giving away free beer in the Safe City?"

Title: Re: fork in the road variation
Post by riddler358 on May 10^th, 2016, 12:52pm

on 05/10/16 at 09:00:41, towr wrote:

[hide]and getting him to do something other than just answering question is valid solution,[/hide]

[hide]can you please do that? <- that's a question :D[/hide]

Title: Re: fork in the road variation
Post by riddler358 on May 11^th, 2016, 2:22pm

i just thought this riddle is really educational
and really cool

did you guys ever encountered such version?

i'm asking cause i kinda had idea of it on my own, and my first intended solution was to ask about "right" way, and this really cool educational solution came later