Day 7: Bridge Repair

Megathread guidelines

  • Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
  • You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://topaz.github.io/paste/ if you prefer sending it through a URL

FAQ

  • Andy@programming.dev
    3·
    17 days ago

    Factor

    spoiler 
    TUPLE: equation value numbers ;
C: <equation> equation

: get-input ( -- equations )
  "vocab:aoc-2024/07/input.txt" utf8 file-lines [
    split-words unclip but-last string>number
    swap [ string>number ] map <equation>
  ] map ;

: possible-quotations ( funcs numbers -- quots )
  dup length 1 -
  swapd all-selections
  [ unclip swap ] dip
  [ zip concat ] with map
  swap '[ _ prefix >quotation ] map ;

: possibly-true? ( funcs equation -- ? )
  [ numbers>> possible-quotations ] [ value>> ] bi
  '[ call( -- n ) _ = ] any? ;

: solve ( funcs -- n )
  get-input
  [ possibly-true? ] with filter
  [ value>> ] map-sum ;

: part1 ( -- n )
  { + * } solve ;

: _|| ( m n -- mn )
  [ number>string ] bi@ append string>number ;

: part2 ( -- n )
  { + * _|| } solve ;