using System; using System.Collections.Generic; using System.Data; using System.Data.Common; using System.IO; using System.Linq; using AdvenOfCode.Contracts; using Microsoft.Z3; namespace AoC_2025; public class Day10 : IPuzzleSolver { private (uint lamps, (int[] buttons, uint buttonsMap)[] buttons, int[] joltages)[] ParsePuzzleInput(string path) { var puzzleInput = File.ReadAllLines(path) .Where(line => !string.IsNullOrWhiteSpace(line)) .Select(line => line.Split(' ', StringSplitOptions.RemoveEmptyEntries)) .Select(instruction => instruction switch { [var lamps, ..var buttons, var joltages] => (lamps: lamps[1..^1], buttons, joltages: joltages[1..^1]), _ => throw new DataException("Misaligned data") }) .OrderBy(inst => inst.lamps.Length) .ToArray(); var lamps = puzzleInput .Select(input => input.lamps) .Select(lamps => lamps.Index()) .Select(ixlamps => ixlamps.Aggregate((uint)0L, (acc, ixLamp) => acc | ((uint)(ixLamp.Item == '#' ? 1L : 0L) << ixLamp.Index))) .ToArray(); var buttons = puzzleInput .Select(input => input.buttons) .Select(buttons => buttons .Select(button => button[1..^1] .Split(',', StringSplitOptions.RemoveEmptyEntries) .Select(lampIndex => int.Parse(lampIndex)) .ToArray()) .Select(lampIndexes => (lampIndexes, lampIndexes.Aggregate((uint)0L, (acc, lampIndex) => acc | ((uint)1 << lampIndex)))) .ToArray()) .ToArray(); var joltages = puzzleInput .Select(input => input.joltages) .Select(joltage => joltage .Split(',', StringSplitOptions.RemoveEmptyEntries) .Select(jolt => int.Parse(jolt)) .ToArray()) .ToArray(); var res = lamps .Zip(buttons, (lamp, button) => (lamp, button)) .Zip(joltages, (bl, joltage) => (bl.lamp, bl.button, joltage)) .ToArray(); return res; } public long SolvePart1(string pathToPuzzleInput) { var instructions = ParsePuzzleInput(pathToPuzzleInput); var minCounts = instructions .Select(ins => GetMinCountButtonPressesForLamps(ins.lamps, [..ins.buttons.Select(b => b.buttonsMap)])) .ToArray(); return minCounts.Sum(); } public long SolvePart2(string pathToPuzzleInput) { var instructions = ParsePuzzleInput(pathToPuzzleInput); var minCounts = instructions .Select(ins => GetMinCountButtonPressesForJoltages(ins.joltages, [..ins.buttons.Select(b => b.buttons)])) .ToArray(); var sum = minCounts.Sum(); return sum; } private long GetMinCountButtonPressesForLamps(uint lamps, uint[] buttons) { var presses = 0L; HashSet lampStates = [lamps]; while (lampStates.All(state => state > 0) && presses < 100) { lampStates = lampStates .Select(lampState => GetLampStates(lampState, buttons)) .Aggregate((current, states) => [..current,..states]) .ToHashSet(); presses++; } return presses; } private uint[] GetLampStates(uint lampState, uint[] buttons) { var states = buttons .Where(button => (lampState & button) > 0) .Select(button => lampState ^ button); return [..states]; } private long GetMinCountButtonPressesForJoltages(int[] joltages, int[][] buttons) { using var context = new Context(); var optimize = context.MkOptimize(); var variables = Enumerable.Range(0, buttons.Length) .Select(ix => context.MkIntConst($"n{ix}")) .ToArray(); foreach (var variable in variables) { optimize.Add(variable >= 0); } var zero = context.MkInt(0); foreach (var (i, joltage) in joltages.Index()) { var equation = zero + zero; foreach (var (b, button) in buttons.Index()) { if(button.Contains(i)) equation += variables[b]; } optimize.Add(context.MkEq(equation, context.MkInt(joltage))); } var sumVariables = variables.Aggregate(zero + zero, (current, variable) => current + variable); optimize.MkMinimize(sumVariables); optimize.Check(); var answerExpression = optimize.Model.Eval(sumVariables); var answer = answerExpression is IntNum number ? number.Int64 : 0; return answer; } }