@@ -28,34 +28,34 @@ object Day16:
2828 cost.toMap
2929 end bfs
3030
31- def explore (input : Seq [String ], youInitial : Int , elephantInitial : Int ): Int =
31+ def explore (input : Seq [String ], initial : Int ): Map [ Set [ String ], Int ] =
3232 val (valves, distance, todo) = parse(input)
33- val cache = collection.mutable.Map [(Set [String ], Set [String ]), Int ]().withDefaultValue(- 1 )
34- 35- def step (todo : Set [String ], you : String , elephant : String , youTime : Int , elephantTime : Int , pressure : Int ): Unit =
36- val key = (Set (you, elephant), todo)
37- if cache(key) >= pressure then return else cache(key) = pressure
38- 39- for next <- todo do
40- val remaining = youTime - distance(you)(next)
41- if remaining > 0 then
42- val extra = remaining * valves(next).flow
43- step(todo - next, next, elephant, remaining, elephantTime, pressure + extra)
44- 45- for next <- todo do
46- val remaining = elephantTime - distance(elephant)(next)
47- if remaining > 0 then
48- val extra = remaining * valves(next).flow
49- step(todo - next, you, next, youTime, remaining, pressure + extra)
33+ val score = collection.mutable.Map [Set [String ], Int ]().withDefaultValue(0 )
34+ 35+ def step (todo : Set [String ], done : Set [String ], from : String , time : Int , pressure : Int ): Unit =
36+ score(done) = score(done).max(pressure)
37+ for
38+ next <- todo
39+ remaining = time - distance(from)(next)
40+ if remaining > 0
41+ extra = remaining * valves(next).flow
42+ do step(todo - next, done + next, next, remaining, pressure + extra)
5043 end step
5144
52- step(todo, " AA " " AA" youInitial, elephantInitial , 0 )
53- cache.values.max
45+ step(todo, Set () , " AA" initial , 0 )
46+ score.toMap
5447 end explore
5548
56- def part1 (input : Seq [String ]): Int = explore(input, 30 , 0 )
49+ def part1 (input : Seq [String ]): Int = explore(input, 30 ).values.max
5750
58- def part2 (input : Seq [String ]): Int = explore(input, 26 , 26 )
51+ def part2 (input : Seq [String ]): Int =
52+ val sets = explore(input, 26 )
53+ val disjoint = for
54+ (you, score1) <- sets
55+ (elephant, score2) <- sets
56+ if you.intersect(elephant).size == 0
57+ yield score1 + score2
58+ disjoint.max
5959
6060 def main (args : Array [String ]): Unit =
6161 val data = io.Source .fromResource(" AdventOfCode2022/Day16.txt"
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