day14-1.prdc

l]{φ44-}SW}m"FUEL"Ho{::¨{\›#Î}b=†q-u)H=M\)I\u÷M\2÷{~\iI*Hm}y;}CHÆ .. 65 bytes

{
l] .. list of lines
{ .. map lines as:
  φ44-} .. filtering by not 44 (",")
  S .. stringify (sad, we shouldn't need this, filter is broken)
  W .. breaking into words
}m
"FUEL"Ho .. set "FUEL" to 1 in the default hoard
.. Repeatedly pick out something on no left sides, delete it, and convert its costs in the hoard.
{
  :: .. copy the master list twice
  ¨ .. flatten the top copy
  { .. block takes a list entry and a flattened list
    \ .. swap
    › .. get last word in list entry
    # .. count the number of times the word appears in the list
    Î .. check if it equals 1
  }b= .. bind to the flattened list and find the first entry satisfying this
  .. we now have an entry to eliminate, and below it the old master list
  †q-u .. delete it. stack: new master list, current handling entry

  )  .. unsnoc to get rest-of-list, last word
  H= .. get how many of it we need so far
  M  .. negate: this is a trick to extract rounding-up division later
  \  .. swap: -needed, rest-of-list
  )I .. unsnoc again and convert to number: this is how much the recipe produces
  \u .. swap under: rest-of-list, -needed, produced
  ÷M .. integer division and negate: this is the number of copies of this recipe
  \  .. swap again. stack: copies needed, rest-of-list
  2÷ .. divide into pairs, discarding leftovers
  { .. for each pair:
    ~ .. expand. stack: copies, consumption_as_string, name
    \i .. swap name in
    I* .. convert consumption to integer and map
    Hm .. modify hoard by adding
  }y .. bind the copies underneath and map
  ;  .. this produced an empty list, don't need it
}C .. Peekdo
.. explicit version: "ORE"H=, but for reasonable recipe sets it will just be
.. the maximum value ever needed for any ingredient, so just get that
HÆ
};