Note that there are two instances of ^: in the tree.
5!:4 <'f'
-- [
│ -- 1
│ +- }.
│ │ -- [:
│ --+ -----+- <:
│ │ │ │ L- [
│ │ L----+- |.
│ -- ^: -+ L- ]
--+ │ │ -- 1
│ │ │ +- <
+- ^: -+ L-+ -- [:
│ │ L----+- #
│ │ L- ]
│ L- _
│
│ -- [:
L------+- i.
L- ]
Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Linda Alvord
Sent: Saturday, April 27, 2013 11:47 AM
To: [email protected]
Subject: Re: [Jprogramming] rosettacode
Jose, That's it. Here it is!
f=: 13 :'x ([ (1 }. ([: <:[) |. ])^:(1 <[: #])^:_ [:i.]) y'
4 f 38
37
Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Jose Mario
Quintana
Sent: Saturday, April 27, 2013 9:59 AM
To: Programming forum
Subject: Re: [Jprogramming] rosettacode
4 ([ (1 }. <:@[ |. ])^:(1 < #@])^:_ i.@]) 38
37
On Apr 27, 2013 4:47 AM, "Linda Alvord" <[email protected]> wrote:
> David had the right answer of 37 as the best position to survive when
> every 4th prisoner is killed in a group of 38. Here's a new version
> now that I understand the problem better.
>
> jolla=: dyad define
> K=:i.y
> while. 1<$K do. K=:1}.(<:x)|.K end.
> K
> )
>
> 3 jolla 41
> 30
> 4 jolla 38
> 37
>
> I still think there is a "one liner" in its future, but I'm not too
> good at that yet.
>
> http://rosettacode.org/wiki/Josephus_problem#J
>
> Linda
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Linda
> Alvord
> Sent: Thursday, April 25, 2013 12:54 PM
> To: [email protected]
> Subject: Re: [Jprogramming] rosettacode
>
> If there are 38 people in a line and every 4th on is killed, where
> would you stand?
>
>
> josephus =: dyad define NB. explicit form, assume executioner starts
> at position 0
> NB. use: SKIP josephus NUMBER_OF_PRISONERS
> N =: y
> K =: N | x
> EXECUTIONER =: 0
> PRISONERS =: i. N
> kill =: ] #~ (~: ([: i. #))
> while. 1 (< #) PRISONERS do.
> EXECUTIONER =: (# PRISONERS) | <: K + EXECUTIONER
> PRISONERS =: EXECUTIONER kill PRISONERS
> end.
> )
>
> 3 josephus 41
> 30
> 4 josephus 38
> 37
>
>
> jolla=: dyad define
> B=:_1}"1 ((>.y%x) ,x)$i.y
> G=:(-.2|y)|.(-.(i.y) e. B)#i.y
> while. y>$B do.
> B=:B,_1{"1((>.($G)%x) ,x)$G
> G=:(-.(i.y) e. B)#i.y
> end.
> _1}B
> )
>
> 3 jolla 41
> 30
> 4 jolla 38
> 18
>
> David Lambert's function chooses the 37th position. Mine chooses the e.
> Where would you stand?
>
> Linda
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of David
> Ward Lambert
> Sent: Thursday, April 18, 2013 11:20 PM
> To: programming
> Subject: [Jprogramming] rosettacode
>
> Please modify these new entries as you please:
> http://rosettacode.org/wiki/Josephus_problem#J
>
> http://rosettacode.org/wiki/Continued_fraction/Arithmetic/Construct_fr
> om_rat
> ional_number#J
> The continued fraction solution has some oddities. Returning _ to
> signal "finished" converts the output vector to floating point.
> That's why I excluded the 314285714 100000000x example. The `y is 8'
> input to r2cf__CF is arbitrary and I have to strip it with _ from the
output vector.
>
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>
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>
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