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Still non-working part 2. But I have an idea.

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Chris Hodges 2025-12-10 21:43:08 +01:00
parent ccc3fdad4c
commit 7495f9e378
1 changed files with 62 additions and 9 deletions
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71
src/aoc2025/Day10.kt
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@ -1,8 +1,10 @@
package aoc2025
import calcCanonicalPrimesSieveOfEratosthenes
import println
import readInput
import splitInts
import java.math.BigInteger
import java.util.*
/*
@ -29,7 +31,6 @@ fun main() {
val toggles =
stuff.drop(1).dropLast(1)
.map { it.removeSurrounding("(", ")").splitInts(",").fold(0) { acc, v -> acc + (1 shl v) } }
.sortedByDescending { it.countOneBits() }
.toIntArray()
val joltages = stuff.last().removeSurrounding("{", "}").splitInts(",").toIntArray()
machines.add(Machine(machSize, target, toggles, joltages))
@ -93,6 +94,63 @@ fun main() {
fun part2(input: List<String>): Int {
val machines = parse(input)
val primes = calcCanonicalPrimesSieveOfEratosthenes(10000)
var sumButts = 0
for (m in machines) {
println()
val maxJoltage = m.joltage.max()
val numBits = 32 - maxJoltage.countLeadingZeroBits()
val bigTarget = m.joltage.foldIndexed(BigInteger.ZERO) { index, acc, i -> acc.plus(BigInteger.valueOf(i.toLong()).shiftLeft(numBits * index)) }
val bigToggles = ArrayList<Pair<BigInteger, BigInteger>>()
for (t in m.toggles) {
var tt = t
var bigToggle = BigInteger.ZERO
var shift = 0
while (tt > 0) {
if (tt and 1 != 0) {
bigToggle = bigToggle.plus(BigInteger.ONE.shiftLeft(shift))
}
shift += numBits
tt = tt shr 1
}
val maxValue = bigTarget.divide(bigToggle).and(BigInteger.ONE.shiftLeft(numBits).minus(BigInteger.ONE)).toInt() + 1
println(maxValue)
if (maxValue > 0) {
bigToggles.add(bigToggle to BigInteger.valueOf(maxValue.toLong()))
}
}
var presses = BigInteger.ONE
var leastFingers = Integer.MAX_VALUE
val maxPresses = bigToggles.fold(BigInteger.ONE) { acc, bt -> acc.multiply(bt.second) }
while (presses <= maxPresses) {
var pe = 0
var pr = presses
var bt = bigTarget
var fingers = 0
while (pe < bigToggles.size && pr > BigInteger.ZERO) {
val f = pr.mod(bigToggles[pe].second)
fingers += f.toInt()
if (fingers > leastFingers) break
bt = bt.minus(bigToggles[pe].first.multiply(f))
if (bt <= BigInteger.ZERO) break
pr = pr.divide(bigToggles[pe].second)
pe++
}
if (bt == BigInteger.ZERO) {
leastFingers = leastFingers.coerceAtMost(fingers)
break
}
presses = presses.plus(BigInteger.ONE)
}
println(leastFingers)
sumButts += leastFingers
}
return sumButts
}
fun part2old(input: List<String>): Int {
val machines = parse(input)
var sumButts = 0
for (m in machines) {
// generate toggles and calculate the global maximum of toggle presses for this toggle
@ -129,12 +187,7 @@ fun main() {
// press all buttons regarding their minimal count (if any)
for (t in toggles) {
if (pressCount[t.idx] + t.min > t.max || !applyJoltage(
jolts,
t,
times = t.min
)
) throw IllegalStateException()
if (pressCount[t.idx] + t.min > t.max || !applyJoltage(jolts, t, times = t.min)) throw IllegalStateException()
pressCount[t.idx] += t.min
}
// this is the starting point for the exhaustive search
@ -151,7 +204,7 @@ fun main() {
}
for (t in toggles) {
if (tc[t.idx] + 2 <= t.max) {
val maxTimes = findMaxButtonPresses(j, t)
val maxTimes = 1//findMaxButtonPresses(j, t)
if (maxTimes > 0) {
val nj = j.copyOf()
if (applyJoltage(nj, t, maxTimes)) {
@ -178,7 +231,7 @@ fun main() {
val testInputPart2Result = part2(testInput)
println("Part 2 Test: $testInputPart2Result")
check(testInputPart1Result == 7)
//check(testInputPart2Result == 33)
check(testInputPart2Result == 33)
val input = readInput("aoc2025/Day10")
part1(input).println()