At 13:43 -0500 2009/12/07, Richard Kubina wrote:
>..well the >: to i.1000 is silly... a slight fix:
>
> >./(#~ (= (|.&.":)"0)) ,*/~i.1000
>
>Sorry for double post, this is exciting (:
I agree with Don that your use of &. is cute. Adding one more token (
~. ) to only work on unique values would speed up your algorithm by a
factor of 4 -
>./(#~ (= (|.&.":)"0)) ~. ,*/~i.1000
A little different and more explicit route would be -
maxpal =: 3 : '>./(*./zd=|.zd)#z[zd=.''0123456789''i.|:":,.z=.~.,*/~i.y'
which is considerably faster. I think it is easier to parse the
explicit verb than a generated tacit one:
13 : '>./(*./zd=|.zd)#z[zd=.''0123456789''i.|:":,.z=.~.,*/~i.y'
([: ('0123456789' i. [: |: [: ": ,.) [: ~. [: , [: */~ i.) ([: >./
([: ([: *./ ] = |.) [) # ]) [: ~. [: , [: */~ i.
And the generated tacit one is a little slower than the explicit one,
the (normalized) time comparisons are:
Time Expression
____ _______________________
1 >./(#~ (= (|.&.":)"0)) ,*/~i.1000
0.259 >./(#~ (= (|.&.":)"0)) ~. ,*/~i.1000
0.026 >./(*./zd=|.zd)#z[zd=.'0123456789'i.|:":,.z=.~.,*/~i.1000
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