132 lines
4.2 KiB
C#
132 lines
4.2 KiB
C#
using System;
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using System.Collections.Generic;
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using System.Data.Common;
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using System.IO;
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using System.Linq;
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using AdvenOfCode.Contracts;
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using Coordinate = (int x, int y, int z);
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namespace AoC_2025;
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public class Day08
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{
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private Coordinate[] ParsePuzzleInput(string path)
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{
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var puzzleInput = File.ReadAllLines(path)
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.Where(line => !string.IsNullOrWhiteSpace(line))
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.Select(line => line.Split(',', StringSplitOptions.RemoveEmptyEntries).Select(str => int.Parse(str)).ToArray())
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.Select(numbers => (numbers[0], numbers[1], numbers[2]))
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.ToArray();
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return puzzleInput;
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}
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public long SolvePart1(string pathToPuzzleInput, int amountToConnect)
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{
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var points = ParsePuzzleInput(pathToPuzzleInput);
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var pointPairs = GetAllCombinationsSortedByDistance(points);
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var circuits = CombineCircuits(amountToConnect, points, pointPairs);
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return circuits
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.Select(circuit => circuit.Count)
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.OrderDescending()
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.Take(3)
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.Aggregate((acc, next) => acc * next);
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}
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public long SolvePart2(string pathToPuzzleInput)
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{
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var points = ParsePuzzleInput(pathToPuzzleInput);
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var pointPairs = GetAllCombinationsSortedByDistance(points);
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var lastConnected = LastCombinedConnectAllCircuits(points, pointPairs);
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return lastConnected.a.x * lastConnected.b.x;
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}
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private List<List<Coordinate>> CombineCircuits(int amountToConnect, Coordinate[] points,
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(Coordinate pointA, Coordinate pointB)[] pointPairs)
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{
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var circuits = points.Select(p => new List<Coordinate>() { p }).ToList();
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for (var i = 0; i < amountToConnect; i++)
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{
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var nextToConnect = pointPairs[i];
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circuits = AddToCircuits(nextToConnect.pointA, nextToConnect.pointB, circuits);
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}
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return circuits;
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}
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private (Coordinate a, Coordinate b) LastCombinedConnectAllCircuits(Coordinate[] points,
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(Coordinate pointA, Coordinate pointB)[] pointPairs)
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{
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var circuits = points.Select(p => new List<Coordinate>() { p }).ToList();
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var lastConnected = pointPairs.First();
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var i = 0;
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while(circuits.Count > 1)
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{
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var nextToConnect = pointPairs[i++];
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circuits = AddToCircuits(nextToConnect.pointA, nextToConnect.pointB, circuits);
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lastConnected = nextToConnect;
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}
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return lastConnected;
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}
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private double GetDistance(Coordinate a, Coordinate b)
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{
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return Math.Sqrt(Math.Pow(a.x - b.x, 2) + Math.Pow(a.y - b.y, 2) + Math.Pow(a.z - b.z, 2));
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}
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private List<List<Coordinate>> AddToCircuits(Coordinate a, Coordinate b, List<List<Coordinate>> circuits)
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{
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var circuitToAddBTo = circuits.FirstOrDefault(circuit => circuit.Contains(a));
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var circuitToAddATo = circuits.FirstOrDefault(circuit => circuit.Contains(b));
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if (circuitToAddATo == null && circuitToAddBTo == null)
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{
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circuits.Add([a, b]);
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return circuits;
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}
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if (circuitToAddATo == circuitToAddBTo)
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{
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return circuits;
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}
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if (circuitToAddATo != null && circuitToAddBTo != null)
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{
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circuits.Remove(circuitToAddATo);
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circuits.Remove(circuitToAddBTo);
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circuits.Add([..circuitToAddATo, ..circuitToAddBTo]);
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return circuits;
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}
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if (circuitToAddATo != null)
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{
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circuitToAddATo.Add(a);
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}
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else
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{
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circuitToAddBTo!.Add(b);
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}
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return circuits;
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}
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private (Coordinate pointA, Coordinate pointB)[] GetAllCombinationsSortedByDistance(Coordinate[] coordinates)
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{
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var combinations = Combinations(coordinates)
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.OrderBy(x => GetDistance(x.a, x.b))
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.ToArray();
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return combinations;
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}
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private IEnumerable<(TValue a, TValue b)> Combinations<TValue>(IEnumerable<TValue> values)
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{
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var enumerated = values.ToArray();
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return enumerated
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.SelectMany((valueA, ix) => enumerated.Skip(ix + 1).Select(valueB => (valueA, valueB)));
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}
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} |