Day 10. Part 2 doesn't terminate in time and space yet.

src/aoc2025/Day10.kt

@@ -0,0 +1,123 @@
+package aoc2025
+
+import println
+import readInput
+import splitInts
+import java.util.*
+
+/*
+--- Day 10: Factory ---
+https://adventofcode.com/2025/day/10
+*/
+fun main() {
+
+    val inlineTestInput = """
+[.##.] (3) (1,3) (2) (2,3) (0,2) (0,1) {3,5,4,7}
+[...#.] (0,2,3,4) (2,3) (0,4) (0,1,2) (1,2,3,4) {7,5,12,7,2}
+[.###.#] (0,1,2,3,4) (0,3,4) (0,1,2,4,5) (1,2) {10,11,11,5,10,5}
+"""
+
+    data class Machine(val size: Int, val target: Int, val toggles: IntArray, val joltage: IntArray)
+
+    fun parse(input: List<String>): ArrayList<Machine> {
+        val machines = ArrayList<Machine>()
+        for (i in input) {
+            val stuff = i.split(" ")
+            val machSize = stuff[0].length - 2
+            val target = stuff[0].removeSurrounding("[", "]").foldIndexed(0) { i, acc, ch -> acc + if (ch == '#') (1 shl i) else 0 }
+            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))
+        }
+        return machines
+    }
+
+    fun part1(input: List<String>): Int {
+        val machines = parse(input)
+        var sumButts = 0
+        for (m in machines) {
+            val pq = PriorityQueue<Pair<Int, Int>>(compareBy { it.second })
+            val killSet = HashSet<Int>()
+            pq.add(0 to 0)
+            while (pq.isNotEmpty()) {
+                val (v, bi) = pq.poll()
+                if (v == m.target) {
+                    sumButts += bi
+                    break
+                }
+                killSet.add(v)
+                for (t in m.toggles) {
+                    val nv = v xor t
+                    if (!killSet.contains(nv)) {
+                        pq.add(nv to bi + 1)
+                    }
+                }
+            }
+        }
+        return sumButts
+    }
+
+    fun part2(input: List<String>): Int {
+        val machines = parse(input)
+        var sumButts = 0
+        // so this is not working in time and space, needs some clever pruning or prime factoring of button presses to reach the target values
+        for (m in machines) {
+            val pq = PriorityQueue(compareBy<Pair<Int, Pair<Int, IntArray>>> { it.second.first }.thenComparing { it.second.second.sum() })
+            pq.add(0 to (0 to m.joltage))
+            val bestMap = HashMap<IntArray, Int>()
+            while (pq.isNotEmpty()) {
+                val (v, bi) = pq.poll()
+                if (bi.second.sum() == 0) {
+                    println("${bi.first}")
+                    sumButts += bi.first
+                    break
+                }
+                //println("$v ${bi.first} ${bi.second.joinToString(",")}")
+                for (t in m.toggles) {
+                    val nv = v xor t
+                    val nj = bi.second.copyOf()
+                    var tt = t
+                    var jp = 0
+                    var valid = true
+                    while (tt != 0) {
+                        if (tt and 1 != 0) {
+                            nj[jp]--
+                            if (nj[jp] < 0) {
+                                valid = false
+                                break
+                            }
+                        }
+                        tt = tt shr 1
+                        jp++
+                    }
+                    if (valid) {
+                        val cache = bestMap[nj]
+                        if (cache == null || cache > bi.first + 1) {
+                            val nbj = (bi.first + 1 to nj)
+                            bestMap[nj] = bi.first + 1
+                            pq.add(nv to nbj)
+                        }
+                    }
+                }
+            }
+        }
+        return sumButts
+    }
+
+    // test if implementation meets criteria from the description, like:
+    val testInput = inlineTestInput.trim().reader().readLines()
+    //val testInput = readInput("aoc2025/Day10_test")
+    val testInputPart1Result = part1(testInput)
+    println("Part 1 Test: $testInputPart1Result")
+    val testInputPart2Result = part2(testInput)
+    println("Part 2 Test: $testInputPart2Result")
+    check(testInputPart1Result == 7)
+    check(testInputPart2Result == 33)
+
+    val input = readInput("aoc2025/Day10")
+    part1(input).println()
+    part2(input).println()
+}