56 lines
1.9 KiB
Smalltalk
56 lines
1.9 KiB
Smalltalk
Object subclass: TrailMap [
|
|
| heightMap scores allDirs |
|
|
scores [^scores]
|
|
|
|
initFor: pos [ ^Set new add: pos; yourself ]
|
|
initScore [ ^Set new ]
|
|
combineScore: score with: other [ score addAll: other. ^score ]
|
|
numberFromScore: score [ ^score size ]
|
|
|
|
initialize [ allDirs := {Posn up. Posn down. Posn left. Posn right}. ]
|
|
heights: hm [ heightMap := hm. self initScores. ]
|
|
initScores
|
|
[ | rows |
|
|
rows := (1 to: heightMap height) collect: [
|
|
:y | (1 to: heightMap width) collect: [
|
|
:x | | pos | pos := Posn x: x y: y.
|
|
((heightMap at: pos) = 9)
|
|
ifTrue: [self initFor: pos]
|
|
ifFalse: [nil]]].
|
|
scores := Grid new rows: rows ]
|
|
|
|
computeScores
|
|
[ (8 to: 0 by: -1) do: [:i | self computeScoresForHeight: i]. ]
|
|
|
|
computeScoresForHeight: h
|
|
[ | h1 | h1 := h + 1.
|
|
heightMap allPosnsDo: [
|
|
:pos |
|
|
(heightMap at: pos) = h ifTrue: [
|
|
| res | res := self initScore.
|
|
allDirs collect: [
|
|
:off | | offp | offp := pos + off.
|
|
((heightMap at: offp) = h1) ifTrue:
|
|
[ res := self combineScore: res with: (scores at: offp) ]].
|
|
scores at: pos put: res ]]]
|
|
|
|
trailheadScores
|
|
[ ^(heightMap allPosnsOf: 0) collect: [:p | self numberFromScore: (scores at: p)] ]
|
|
]
|
|
|
|
TrailMap subclass: TrailMapP2 [
|
|
initFor: pos [^1]
|
|
initScore [^0]
|
|
combineScore: score with: other [^score + other]
|
|
numberFromScore: score [^score]
|
|
]
|
|
|
|
AOC input: [ | rows |
|
|
rows := stdin toLines asArray collect: [
|
|
:line | line asArray collect: [:it | it digitValue]].
|
|
Grid new rows: rows ];
|
|
part1: TrailMap; part2: TrailMapP2;
|
|
result: [ :heights :Class | | map |
|
|
map := Class new heights: heights.
|
|
map computeScores trailheadScores sum ];
|
|
finish.
|