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Code Issues Activity

2023 Day 17 Part 2

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This commit is contained in:
Jeremy Kaplan 2023-12-17 14:17:51 -08:00
commit b44f443bf1
1 changed files with 25 additions and 6 deletions
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31
2023/day17.nim
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@ -97,8 +97,7 @@ type Node = tuple
func `<`(a, b: Node): bool = a.cost < b.cost func `<`(a, b: Node): bool = a.cost < b.cost
func successors(m: Map, state: State): seq[(State, int)] =
iterator successors(m: Map, state: State): (State, int) =
for steps in 1..3: for steps in 1..3:
var pos = state.pos var pos = state.pos
var loss = 0 var loss = 0
@ -106,10 +105,12 @@ iterator successors(m: Map, state: State): (State, int) =
pos = pos.move(state.dir, 1) pos = pos.move(state.dir, 1)
loss += m.loss(pos) loss += m.loss(pos)
yield ((pos, state.dir.cw), loss) result.add ((pos, state.dir.cw), loss)
yield ((pos, state.dir.ccw), loss) result.add ((pos, state.dir.ccw), loss)
proc heatLoss(m: Map, start, goal: Point): int = type Successors = (Map, State) -> seq[(State, int)]
proc heatLoss(m: Map, start, goal: Point, successors: Successors): int =
var queue: HeapQueue[Node] var queue: HeapQueue[Node]
var seen: HashSet[State] var seen: HashSet[State]
@ -136,7 +137,23 @@ proc heatLoss(m: Map, start, goal: Point): int =
proc part1(input: string): int = proc part1(input: string): int =
let text = readFile(input) let text = readFile(input)
let map = parseMap(text) let map = parseMap(text)
map.heatLoss((0, 0), (map.height - 1, map.width - 1)) map.heatLoss((0, 0), (map.height - 1, map.width - 1), successors)
func ultra(m: Map, state: State): seq[(State, int)] =
for steps in 4..10:
var pos = state.pos
var loss = 0
for _ in 1..steps:
pos = pos.move(state.dir, 1)
loss += m.loss(pos)
result.add ((pos, state.dir.cw), loss)
result.add ((pos, state.dir.ccw), loss)
proc part2(input: string): int =
let text = readFile(input)
let map = parseMap(text)
map.heatLoss((0, 0), (map.height - 1, map.width - 1), ultra)
proc timed[T](f: () -> T): T = proc timed[T](f: () -> T): T =
let start = cpuTime() let start = cpuTime()
@ -145,3 +162,5 @@ proc timed[T](f: () -> T): T =
echo timed(proc(): int = part1("input/test.txt")) echo timed(proc(): int = part1("input/test.txt"))
echo timed(proc(): int = part1("input/day17.txt")) echo timed(proc(): int = part1("input/day17.txt"))
echo timed(proc(): int = part2("input/test.txt"))
echo timed(proc(): int = part2("input/day17.txt"))