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Day 22 optimisations

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This commit is contained in:
Beatrice Szilvasy 2024-12-22 07:50:50 +00:00
parent beb0f4a8e7
commit 1e7399f109
1 changed files with 42 additions and 15 deletions
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57
days/day22.st
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@ -3,24 +3,48 @@ Object subclass: Monkey [
history: h [history := h] history: h [history := h]
lastValue [^history at: history size] lastValue [^history at: history size]
collectPricesInto: intoTbl collectPricesInto: intoTbl seen: seenTbl
[ | ch table prices deltas chMod | [ | ch prices deltas key newV prevSeen localBest |
table := Dictionary new.
prices := history collect: [:it | it \\ 10]. prices := history collect: [:it | it \\ 10].
deltas := 2 to: history size collect: [ deltas := 2 to: history size collect: [
:i | (prices at: i) - (prices at: i - 1) + 9]. :i | (prices at: i) - (prices at: i - 1) + 9].
ch := 0. ch := 0. "past four deltas as a base-19 integer"
1 to: 4 do: [ 1 to: 4 do: [:i | ch := 19 * ch + (deltas at: i)].
:i | ch := 20 * ch + (deltas at: i)]. "Accumulate the best value globally, (local variable as a
chMod := 20 raisedTo: 4. 'compiler' optimisation)."
localBest := Monkey bestBananas.
5 to: deltas size do: [ 5 to: deltas size do: [
:i | ch := (20 * ch + (deltas at: i)) \\ chMod. :i | ch := (19 * ch + (deltas at: i)) \\ 130321.
table at: ch ifAbsentPut: [prices at: i + 1]]. "ch is theoretically in the range [0,19^4),
table keysAndValuesDo: [ so add 1 to keep it in array range"
:ch :v | intoTbl at: ch put: v + (intoTbl at: ch ifAbsent: [0])]] key := ch + 1.
(seenTbl at: key) == false ifTrue: [
"Store a linked list of seen values within the table,
to make resetting it easier."
seenTbl at: key put: prevSeen.
prevSeen := key.
newV := (prices at: i + 1) + (intoTbl at: key).
intoTbl at: key put: newV.
newV > localBest ifTrue: [localBest := newV].
]].
Monkey bestBananas: localBest.
"Reset the seen table via the linked list."
[prevSeen notNil] whileTrue: [
| tmp | tmp := seenTbl at: prevSeen.
seenTbl at: prevSeen put: false.
prevSeen := tmp. ]]
] ]
Monkey class extend [ Monkey class extend [
| bestV |
bestBananas: v [bestV := v]
bestBananas [^bestV]
initialize [bestV := 0]
keyDigits [^19]
keyMax [^130321 "19 raisedTo: 4"]
stepSecret: initial times: n stepSecret: initial times: n
[ | s hist | s := initial. [ | s hist | s := initial.
hist := 1 to: n collect: [ hist := 1 to: n collect: [
@ -31,12 +55,15 @@ Monkey class extend [
s ]. s ].
^Monkey new history: {initial},hist ] ^Monkey new history: {initial},hist ]
] ]
Monkey initialize.
AOC input: [ stdin toLines collect: [ AOC input: [ stdin toLines collect: [
:it | Monkey stepSecret: it asNumber times: 2000] ]; :it | Monkey stepSecret: it asNumber times: 2000] ];
part1: [ :monkeys | (monkeys collect: [:it | it lastValue]) sum ]; part1: [ :monkeys | (monkeys collect: [:it | it lastValue]) sum ];
part2: [ :monkeys | | buyMap | buyMap := Dictionary new. part2: [ :monkeys | | buyMap seenMap |
monkeys do: [:it | it collectPricesInto: buyMap]. buyMap := Array new: Monkey keyMax withAll: 0.
buyMap values maximum ]; seenMap := Array new: Monkey keyMax withAll: false.
monkeys do: [:it | it collectPricesInto: buyMap seen: seenMap].
Monkey bestBananas ];
result: [ :monkeys :part | part value: monkeys ]; result: [ :monkeys :part | part value: monkeys ];
finish. finish.