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Re: Re: Re: Re: Re: (Golf) Reversing RPN Notation

by Masem (Monsignor)
on May 21, 2001 at 22:39 UTC ( #82045=note: print w/replies, xml ) Need Help??

in reply to Re: Re: Re: Re: (Golf) Reversing RPN Notation
in thread (Golf) Reversing RPN Notation

Ok, it's probably going to depend on how you decide to pop off the stack. Given "N1 N2 o" in RPN where N1 and N2 are the numbers and o the operation, the LTR should be "N1 o N2".

Yes, '/' would need to be 4. And yes, the second one poses the problem if there's no indication of order being important on an operation ("a op b" not being equal to "b op a"). Chipmunk's got part of the problem with associtivity in his 171 char solution, but I might need to restate the problem to handle this concept; at the time, I was only aiming for a general solution assuming that order didn't matter.

Dr. Michael K. Neylon - || "You've left the lens cap of your mind on again, Pinky" - The Brain
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Re: Re: Re: Re: Re: Re: (Golf) Reversing RPN Notation
by MeowChow (Vicar) on May 22, 2001 at 00:02 UTC
    Almost. The rule that "a op b" != "b op a" is not the same rule as "a op (b op c)" != "(a op b) op c". The former is commutativity, while the latter is associativity.
                   s aamecha.s a..a\u$&owag.print

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[LanX]: he was "meating" Italian monks oO?
[erix]: then again, there are people who do 10 full triathlons on 10 consecutive days, so it must be doable
choroba's friend has done the Pacific Crest Trail, it's 4200 km
LanX Ladies and gentlemen: due to shortages of "Body of Christ" we have to resort to Body of Monks ...
LanX ... buon appetito!
[LanX]: Pacific Crest Trail is really hard stuff
[Eily]: erix he plans to go as far as leuca
[erix]: ah, that's really down at the heel point :)
[Eily]: LanX how dare you imply that I made a typo? It's true but still!

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