We all had the same solution. My version is
# ,@((# , {.);.1~ (~: |.!.0))^:40 "."0 '1113122113'Henry Rich On 12/10/2015 10:16 AM, 'Pascal Jasmin' via Programming wrote:
I did not know fill on |. worked that way. I see it now. neat. ----- Original Message ----- From: Joe Bogner <joebog...@gmail.com> To: programm...@jsoftware.com Sent: Thursday, December 10, 2015 9:40 AM Subject: Re: [Jprogramming] advent 10 Thanks, the fill is needed otherwise it would return the wrong result if the last number is the same as the first. I don't think my version is susceptible to that but would be interested to find an example if it is correct: (,@((#,{.);.1~ _1&(|.!._) ~: ])) (1 1 1 3 2 2 2 1 1 1) 3 1 1 3 3 2 3 1 vs (no fill) (,@((#,{.);.1~ _1&(|.) ~: ])) (1 1 1 3 2 2 2 1 1 1) 1 3 3 2 3 1 You can see this in: Correct: (<;.1~ _1&(|.!._) ~: ]) (1 1 1 3 2 2 2 1 1 1) ┌─────┬─┬─────┬─────┐ │1 1 1│3│2 2 2│1 1 1│ └─────┴─┴─────┴─────┘ Incorrect: (<;.1~ _1&(|.) ~: ]) (1 1 1 3 2 2 2 1 1 1) ┌─┬─────┬─────┐ │3│2 2 2│1 1 1│ └─┴─────┴─────┘ vs On Thu, Dec 10, 2015 at 9:05 AM, 'Pascal Jasmin' via Programming <programm...@jsoftware.com> wrote:You may have gotten lucky with _1&|. (fill not needed afaiu) an improvement to mine, after seeing yours. # ,@( ((# , {. );. 1)~ 1 , 2 ~:/\ ])^:(40) 1 1 1 3 2 2 2 1 1 3 ----- Original Message ----- From: Joe Bogner <joebog...@gmail.com> To: programm...@jsoftware.com Sent: Thursday, December 10, 2015 8:47 AM Subject: Re: [Jprogramming] advent 10 Clever use of the state machine. I enjoy seeing those... Here's mine: NB. part 1 # (,@((#,{.);.1~ _1&(|.!._) ~: ]))^:40 input=:(1 1 1 3 2 2 2 1 1 3) 252594 NB. part 2 # (,@((#,{.);.1~ _1&(|.!._) ~: ]))^:50 input=:(1 1 1 3 2 2 2 1 1 3) 3579328 To explain, we are going to use cut to split the array when the number is different than the previous number Return 1 if the number is different than the previous number, otherwise 0 (_1&(|.!._) ~: ]) (1 1 1 3 2 2 2 1 1 3) 1 0 0 1 1 0 0 1 0 1 Apply cut to the sequence to cut into intervals (<;.1~ _1&(|.!._) ~: ]) (1 1 1 3 2 2 2 1 1 3) ┌─────┬─┬─────┬───┬─┐ │1 1 1│3│2 2 2│1 1│3│ └─────┴─┴─────┴───┴─┘ Instead of boxing, return count of the first item in each interval ((#,{.);.1~ _1&(|.!._) ~: ]) input=:(1 1 1 3 2 2 2 1 1 3) 3 1 1 3 3 2 2 1 1 3 from here, just ravel and count the numbers On Thu, Dec 10, 2015 at 3:55 AM, Ryan Eckbo <ec...@cim.mcgill.ca> wrote:Oops, typo in the title - this is for day 10, not 8. On 10 Dec 2015, at 19:52, Ryan Eckbo wrote:A previous advent answer got me thinking about state machines, so I wrote one for this problem. The extra initial state ruins the natural mapping between states and numbers, but I think it's unavoidable? Also someone could probably write a clever verb to generate the table. NB. state machine -- can be confusing because rows/states 1,2,3,.. represent numbers 0,1,2,.. S=: 0 10#: 10* ". }. [;._2 noun define 0 1 2 3 4 5 6 7 8 9 1.1 2.1 3.1 4.1 5.1 6.1 7.1 8.1 9.1 10.1 NB. initial 1.0 2.2 3.2 4.2 5.2 6.2 7.2 8.2 9.2 10.2 NB. 0 1.2 2.0 3.2 4.2 5.2 6.2 7.2 8.2 9.2 10.2 NB. 1 1.2 2.2 3.0 4.2 5.2 6.2 7.2 8.2 9.2 10.2 NB. 2 1.2 2.2 3.2 4.0 5.2 6.2 7.2 8.2 9.2 10.2 NB. 3 1.2 2.2 3.2 4.2 5.0 6.2 7.2 8.2 9.2 10.2 NB. 4 1.2 2.2 3.2 4.2 5.2 6.0 7.2 8.2 9.2 10.2 NB. 5 1.2 2.2 3.2 4.2 5.2 6.2 7.0 8.2 9.2 10.2 NB. 6 1.2 2.2 3.2 4.2 5.2 6.2 7.2 8.0 9.2 10.2 NB. 7 1.2 2.2 3.2 4.2 5.2 6.2 7.2 8.2 9.0 10.2 NB. 8 1.2 2.2 3.2 4.2 5.2 6.2 7.2 8.2 9.2 10.0 NB. 9 ) v=:[: ,@:((#,{.)every) (0;S)&;: smoutput $ v^:40 Input=: 1 1 1 3 2 2 2 1 1 3 smoutput $ v^:50 Input ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
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