From 696151a23c1c69867420d0e84a2bd027da57683e Mon Sep 17 00:00:00 2001 From: TiagoRG Date: Fri, 9 Jun 2023 00:43:55 +0100 Subject: [PATCH] [2022] Day9 added --- Utils/Extensions.cs | 30 ++++++++++ Year2022/Day9.cs | 134 ++++++++++++++++++++++++-------------------- 2 files changed, 103 insertions(+), 61 deletions(-) diff --git a/Utils/Extensions.cs b/Utils/Extensions.cs index 3f8dfbb..7a99c1c 100644 --- a/Utils/Extensions.cs +++ b/Utils/Extensions.cs @@ -2,6 +2,16 @@ namespace AdventOfCode.Utils; public static class Extensions { + public static int Signal(this int x) + { + return x switch + { + < 0 => -1, + > 0 => 1, + _ => 0 + }; + } + /// /// Returns a slice of the given list /// @@ -76,4 +86,24 @@ public static class Extensions ret.Add(entry.Key, entry.Value.Clone()); return ret; } + + public static void Fill(this List list, int count, T element) + where T : ICloneable + { + for (int i = 0; i < count; i++) + list.Add(element); + } + + public static void Fill(this List> list, int count, List element) + { + for (int i = 0; i < count; i++) + list.Add(element.Clone()); + } + + public static void Set(this List list, int index, T element) + { + List backup = list.Clone(); + list.Clear(); + for (int i = 0; i < list.Count; i++) list.Add(i == index ? element : list[i]); + } } \ No newline at end of file diff --git a/Year2022/Day9.cs b/Year2022/Day9.cs index b9794f5..dcf8849 100644 --- a/Year2022/Day9.cs +++ b/Year2022/Day9.cs @@ -1,87 +1,99 @@ +using AdventOfCode.Utils; + namespace AdventOfCode.Year2022; public class Day9 { - private static readonly List<(char, int)> Moves = new(); - private static readonly Dictionary> Position = new() - { - ['H'] = new List(), - ['T'] = new List() - }; - public Day9() { Console.WriteLine("Day9 Solution"); + List<(char, int)> moves = new List<(char, int)>(); File.ReadAllLines("inputs/day9.txt").ToList().ForEach(line => { string[] split = line.Split(" "); - Moves.Add((Convert.ToChar(split[0]), Convert.ToInt32(split[1]))); + moves.Add((Convert.ToChar(split[0]), Convert.ToInt32(split[1]))); }); - Console.WriteLine($"Part1 Result: {Part1()}"); - Console.WriteLine($"Part2 Result: {Part2()}"); + Console.WriteLine($"Part1 Result: {GetPositionCount(moves, 2)}"); + Console.WriteLine($"Part2 Result: {GetPositionCount(moves, 10)}"); Console.WriteLine("\n=============================\n"); } - private static int Part1() + private static int GetPositionCount(List<(char, int)> moves, int knots) { - Position['H'] = new[] {0, 0}.ToList(); - Position['T'] = new[] {0, 0}.ToList(); - HashSet<(int, int)> usedPositions = new HashSet<(int, int)>(); + List> currentPositions = new List>(); + currentPositions.Fill(knots, new List(new[]{0,0})); + HashSet<(int, int)> tailHistory = new HashSet<(int, int)>(); - foreach ((char, int) move in Moves) - { - List head = Position['H']; - List tail = Position['T']; - for (int i = 0; i < move.Item2; i++) + foreach ((char, int) move in moves) + for (int moveN = 0; moveN < move.Item2; moveN++) { - if (move.Item1 == 'U') + int[] vector = GetVector(move.Item1); + int[] previousTailPosition = currentPositions[0].ToArray(); + currentPositions[0] = UpdateHead(vector, currentPositions[0]); + for (int tailN = 0; tailN < knots-1; tailN++) { - head[1]++; - if (ValidatePosition()) continue; - tail[1]++; - tail[0] += head[0] - tail[0]; + int[] nextPreviousTailPosition = currentPositions[tailN + 1].ToArray(); + currentPositions[tailN + 1] = UpdateTail(currentPositions[tailN], currentPositions[tailN + 1], previousTailPosition); + previousTailPosition = nextPreviousTailPosition; + if (tailN == knots - 2) + tailHistory.Add((currentPositions[knots - 1][0], currentPositions[knots - 1][1])); } - else if (move.Item1 == 'D') - { - head[1]--; - if (ValidatePosition()) continue; - tail[1]--; - tail[0] += head[0] - tail[0]; - } - else if (move.Item1 == 'R') - { - head[0]++; - if (ValidatePosition()) continue; - tail[0]++; - tail[1] += head[1] - tail[1]; - } - else if (move.Item1 == 'L') - { - head[0]--; - if (ValidatePosition()) continue; - tail[0]--; - tail[1] += head[1] - tail[1]; - } - usedPositions.Add((tail[0], tail[1])); } - } - return usedPositions.Count; + + return tailHistory.Count; } - private static int Part2() + private static List UpdateHead(int[] vector, List currentPosition) { - Position['H'] = new[] {0, 0}.ToList(); - Position['T'] = new[] {0, 0}.ToList(); - HashSet<(int, int)> usedPositions = new HashSet<(int, int)>(); - - foreach ((char, int) move in Moves) - { - - } - - return usedPositions.Count; + currentPosition[0] += vector[0]; + currentPosition[1] += vector[1]; + return new List { currentPosition[0], currentPosition[1] }; } - private static bool ValidatePosition() - => Position['H'][0] - Position['T'][0] is > -2 and < 2 && Position['H'][1] - Position['T'][1] is > -2 and < 2; + private static List UpdateTail(List currentHeadPosition, List currentTailPosition, int[] previousTailPosition) + { + List head = new List + { + currentHeadPosition[0] - previousTailPosition[0], + currentHeadPosition[1] - previousTailPosition[1] + }; + + if (Math.Abs(currentHeadPosition[0] - currentTailPosition[0]) > 1 || + Math.Abs(currentHeadPosition[1] - currentTailPosition[1]) > 1) + { + if (previousTailPosition[0] == currentTailPosition[0] || + previousTailPosition[1] == currentTailPosition[1]) + return new List + { + currentTailPosition[0] + head[0], + currentTailPosition[1] + head[1] + }; + + List difference = new List + { + currentHeadPosition[0] - currentTailPosition[0], + currentHeadPosition[1] - currentTailPosition[1] + }; + + return new List + { + currentTailPosition[0] + difference[0].Signal() * Math.Min(Math.Abs(difference[0]), 1), + currentTailPosition[1] + difference[1].Signal() * Math.Min(Math.Abs(difference[1]), 1) + }; + } + + return currentTailPosition; + } + + private static int[] GetVector(char direction) + { + return direction switch + { + 'U' => new[] { 1, 0 }, + 'D' => new[] { -1, 0 }, + 'R' => new[] { 0, 1 }, + 'L' => new[] { 0, -1 }, + _ => new[] { 0, 0 } + }; + } } \ No newline at end of file