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What a mess.

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Change-Id: I6691ff4ca64b6a2ae6edc38c4e2105130403437a
This commit is contained in:
Chris Hodges 2023-12-20 10:06:56 +01:00
parent 04dc4d6ba9
commit 158ed23e9e
1 changed files with 133 additions and 35 deletions
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168
src/aoc2023/Day20.kt
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@ -1,5 +1,6 @@
package aoc2023
import lcm
import println
import readInput
@ -99,6 +100,14 @@ broadcaster -> a, b, c
%b -> c
%c -> inv
&inv -> a
"""
val inlineTestInput2 = """
broadcaster -> a
%a -> inv, con
&inv -> b
%b -> con
&con -> output
"""
data class Node(
@ -110,7 +119,9 @@ broadcaster -> a, b, c
var stateIdx: Int = 0
)
fun part1(input: List<String>): Long {
data class CacheInfo(val lowPulses: Long, val highPulses: Long, val nextState: BooleanArray)
fun createGraph(input: List<String>): HashMap<String, Node> {
val nodes = HashMap<String, Node>()
for (i in input) {
val (source, targets) = i.split(" -> ")
@ -128,51 +139,138 @@ broadcaster -> a, b, c
for (node in nodes.values) {
node.stateIdx = stateIdx++
for (t in node.targets) {
nodes[t]!!.inputs.add(node.id)
nodes[t]?.inputs?.add(node.id)
}
}
val state = BooleanArray(nodes.size)
val queue = ArrayDeque<String>()
queue.add("broadcaster")
nodes["broadcaster"]!!.signalsIn.add(false)
var lowPulses = 0L
var highPulses = 0L
var cycleCount = 0
do {
val node = nodes[queue.removeFirst()]!!
val signalsIn = node.signalsIn
when (node.type) {
0 -> state[node.stateIdx] = node.signalsIn.single()
1 -> state[node.stateIdx] = state[node.stateIdx] xor (!node.signalsIn.single())
2 -> {
state[node.stateIdx] = !signalsIn.all { it }
}
}
if (state[node.stateIdx]) highPulses += node.targets.size else lowPulses += node.targets.size
node.targets.forEach { nodes[it]!!.signalsIn.add(state[node.stateIdx]) }
node.signalsIn.clear()
queue.addAll(node.targets)
node.targets.forEach { println("${node.id} -${state[node.stateIdx]}> $it") }
cycleCount++
} while (cycleCount < 2 || state.any { it })
return lowPulses * highPulses
return nodes
}
fun part2(input: List<String>): Int {
return 0
fun part1(input: List<String>): Long {
val nodes = createGraph(input)
val state = BooleanArray(nodes.size)
val cache = HashMap<String, CacheInfo>()
var totalLowPulses = 0L
var totalHighPulses = 0L
for (n in 1..1000) {
val stateString = state.joinToString("") { if (it) "1" else "0" }
val cached = cache[stateString]
if (cached != null) {
totalLowPulses += cached.lowPulses
totalHighPulses += cached.highPulses
cached.nextState.copyInto(state)
continue
}
val queue = LinkedHashSet<String>()
queue.add("broadcaster")
nodes["broadcaster"]!!.signalsIn.add(false)
var lowPulses = 1L
var highPulses = 0L
do {
val id = queue.first()
queue.remove(id)
val node = nodes[id]
if (node != null) {
val signalsIn = node.signalsIn
for (signalIn in signalsIn) {
when (node.type) {
0 -> {
state[node.stateIdx] = signalIn
if (state[node.stateIdx]) highPulses += node.targets.size else lowPulses += node.targets.size
node.targets.forEach { nodes[it]?.signalsIn?.add(state[node.stateIdx]) }
queue.addAll(node.targets)
}
1 -> if (!signalIn) {
state[node.stateIdx] = !state[node.stateIdx]
if (state[node.stateIdx]) highPulses += node.targets.size else lowPulses += node.targets.size
node.targets.forEach { nodes[it]?.signalsIn?.add(state[node.stateIdx]) }
queue.addAll(node.targets)
}
2 -> {
state[node.stateIdx] = !node.inputs.all { state[nodes[it]!!.stateIdx] }
if (state[node.stateIdx]) highPulses += node.targets.size else lowPulses += node.targets.size
node.targets.forEach { nodes[it]?.signalsIn?.add(state[node.stateIdx]) }
queue.addAll(node.targets)
}
}
}
node.signalsIn.clear()
}
} while (queue.isNotEmpty())
cache[stateString] = CacheInfo(lowPulses, highPulses, state.copyOf())
totalLowPulses += lowPulses
totalHighPulses += highPulses
}
return totalLowPulses * totalHighPulses
}
fun part2(input: List<String>): Long {
val nodes = createGraph(input)
val state = BooleanArray(nodes.size)
var buttonCount = 0L
val klNode = nodes.values.first { it.targets.contains("rx") }
val periods = LongArray(klNode.inputs.size)
do {
buttonCount++
val queue = LinkedHashSet<String>()
queue.add("broadcaster")
nodes["broadcaster"]!!.signalsIn.add(false)
do {
val id = queue.first()
queue.remove(id)
val node = nodes[id]
if (node != null) {
val signalsIn = node.signalsIn
for (signalIn in signalsIn) {
when (node.type) {
0 -> {
state[node.stateIdx] = signalIn
node.targets.forEach { nodes[it]?.signalsIn?.add(state[node.stateIdx]) }
queue.addAll(node.targets)
}
1 -> if (!signalIn) {
state[node.stateIdx] = !state[node.stateIdx]
node.targets.forEach { nodes[it]?.signalsIn?.add(state[node.stateIdx]) }
queue.addAll(node.targets)
}
2 -> {
state[node.stateIdx] = !node.inputs.all { state[nodes[it]!!.stateIdx] }
node.targets.forEach { nodes[it]?.signalsIn?.add(state[node.stateIdx]) }
queue.addAll(node.targets)
}
}
}
node.signalsIn.clear()
klNode.inputs.forEachIndexed { index, s ->
if (state[nodes[s]!!.stateIdx]) {
if (periods[index] == 0L) {
periods[index] = buttonCount
println("$index $s $buttonCount")
}
}
}
//node.targets.forEach { println("$rxCount: $lowPulses, $highPulses ${node.id} -${state[node.stateIdx]}> $it") }
}
} while (queue.isNotEmpty())
//println("$buttonCount")
} while (periods.any { it == 0L })
return periods.asIterable().lcm()
}
// test if implementation meets criteria from the description, like:
val testInput = inlineTestInput.trim().reader().readLines()
val testInput2 = inlineTestInput2.trim().reader().readLines()
//val testInput = readInput("aoc2023/Day20_test")
val testInputPart1Result = part1(testInput)
println("Part 1 Test: $testInputPart1Result")
val testInputPart2Result = part2(testInput)
println("Part 2 Test: $testInputPart2Result")
check(testInputPart1Result == 0L)
check(testInputPart2Result == 0)
val testInputPart1bResult = part1(testInput2)
println("Part 1b Test: $testInputPart1bResult")
check(testInputPart1Result == 32000000L)
check(testInputPart1bResult == 11687500L)
val input = readInput("aoc2023/Day20")
part1(input).println()