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Day 13 cleanup

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No inputs are linearly dependent, remove the case
This commit is contained in:
Beatrice Szilvasy 2024-12-13 09:46:58 +00:00
parent c4bac0aa4f
commit 6aba245667
1 changed files with 10 additions and 33 deletions
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41
days/day13.st
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@ -1,51 +1,28 @@
Object subclass: Machine [
| vecA vecB prize |
| vecA vecB prize matrix |
parse: line
[ line scanf: 'Button A: X+%d, Y+%d Button B: X+%d, Y+%d Prize: X=%d, Y=%d'
with: [ :aX :aY :bX :bY :pX :pY |
vecA := Posn x: aX y: aY.
vecB := Posn x: bX y: bY.
prize := Posn x: pX y: pY ] ]
prize := Posn x: pX y: pY.
matrix := self computeMatrix ] ]
printOn: st
[ st << '{A: ' << vecA << '; B: ' << vecB << '; P: ' << prize << '}' ]
priceA [^3] priceB [^1]
computeMatrix
[ ^(Mat2 col: vecA col: vecB) inverse
ifNil: [self error: 'Linearly dependent'] ]
solve: offV
[ ^(Mat2 col: vecA col: vecB) inverse
ifNotNil: [
:inv | | vec |
vec := inv *> (prize + offV).
[ | vec | vec := matrix *> (prize + offV).
(vec x isInteger and: [vec y isInteger])
ifTrue: [^vec]
ifFalse: [^nil] ]
ifNil: [
"linearly dependent -- not actually reached"
| slvA slvB |
'Linearly dependent!' displayNl.
slvA := self solveLinDep: vecA.
slvB := self solveLinDep: vecB.
slvA ifNil: [
slvB ifNil: [^nil]
ifNotNil: [^Posn x: 0 y: slvB]].
slvB ifNil: [^Posn x: slvA y: 0].
((slvA * self priceA) <= (slvB * self priceB))
ifTrue: [^Posn x: slvA y: 0]
ifFalse: [^Posn x: 0 y: slvB]] ]
ifTrue: [^vec] ifFalse: [^nil] ]
tokenCost: soln
[ soln ifNil: [^0].
^(soln x * self priceA) + (soln y * self priceB) ]
tokenCost: soln [ soln ifNil: [^0]. ^(soln x * 3) + soln y ]
solveCost: offV [ ^self tokenCost: (self solve: offV) ]
solveLinDep: vec
[ | sf |
sf := prize x / vec x.
(prize y / vec y) = sf ifFalse: [^nil].
sf isInteger ifFalse: [^nil].
^sf ]
]
AOC input: [ stdin chain contents; tokenize: (String with: $<10> with: $<10>);