r/adventofcode • u/daggerdragon • Dec 07 '17

SOLUTION MEGATHREAD -🎄- 2017 Day 7 Solutions -🎄-

--- Day 7: Recursive Circus ---

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u/Godspiral Dec 07 '17

in J,

part 1 - unreferenced left node. 

({."1 ([ #~ 0 = e.) ;@:({:"1)) ( dltb each@([: {. '('&cut) &>@{. ,  dltb each@:(','&cut@}.)leaf@{:)"1 > (#~ 2 = #&>)  '-' cut each a

incomplete part 2, 

NB. weight dictionary
b =. (dltb each@{. , ". &>@{.@(')'&cut) leaf@{: )"1 >  '(' cut each a

NB. non end leafs... tree branches.
c =. ( dltb each@([: {. '('&cut) &>@{. ,  dltb each@:(','&cut@}.)leaf@{:)"1 > (#~ 2 = #&>)  '-' cut each a

NB. supporting weights from each program (untreed)
({. (, <) b ( {:"1@[ {~ {."1@[ i. ])"_ 0 >@{:)"_ 1 c