Add day 14

2025-01-24 10:19:12 +01:00
parent 10429f3302
commit ab3ff19db3
2 changed files with 651 additions and 0 deletions
--- a/Days/Day14.cs
+++ b/Days/Day14.cs
@@ -0,0 +1,151 @@
+using System.Collections.Frozen;
+using System.Numerics;
+using System.Text;
+using Spectre.Console;
+
+namespace AdventOfCode.Days;
+
+public class Day14 : Day
+{
+    public override int Number => 14;
+    public override string Name => "Restroom Redoubt";
+
+    private const int Height = 103;
+    private const int HeightCenter = Height / 2;
+
+    private const int Width = 101;
+    private const int WidthCenter = Width / 2;
+
+    private const int Iterations = 100;
+
+    public override void RunPart1(bool display = true)
+    {
+        var robots = ParseRobots();
+
+        for (var i = 0; i < Iterations; i++)
+        {
+            foreach (var robot in robots)
+            {
+                robot.Position = new Point(
+                    Math.Abs((Width + robot.Position.X + robot.Velocity.X) % Width),
+                    Math.Abs((Height + robot.Position.Y + robot.Velocity.Y) % Height)
+                );
+            }
+        }
+
+        // Compute safety factor
+        var safetyFactor =
+            robots.Count(r => r.Position is { X: < WidthCenter, Y: < HeightCenter }) *
+            robots.Count(r => r.Position is { X: > WidthCenter, Y: < HeightCenter }) *
+            robots.Count(r => r.Position is { X: < WidthCenter, Y: > HeightCenter }) *
+            robots.Count(r => r.Position is { X: > WidthCenter, Y: > HeightCenter });
+
+        if (display)
+        {
+            AnsiConsole.MarkupLine($"[green]Safety factor: [yellow]{safetyFactor}[/][/]");
+        }
+    }
+
+    public override void RunPart2(bool display = true)
+    {
+        var robots = ParseRobots();
+
+        var canvas = new Canvas(Width, Height);
+
+        for (var i = 0; i < int.MaxValue; i++)
+        {
+            for (var x = 0; x < Width; x++)
+            {
+                for (var y = 0; y < Height; y++)
+                {
+                    canvas.SetPixel(x, y, Color.Grey23);
+                }
+            }
+
+            foreach (var robot in robots)
+            {
+                robot.Position = new Point(
+                    Math.Abs((Width + robot.Position.X + robot.Velocity.X) % Width),
+                    Math.Abs((Height + robot.Position.Y + robot.Velocity.Y) % Height)
+                );
+
+                canvas.SetPixel(robot.Position.X, robot.Position.Y, Color.Green1);
+            }
+
+            // Display grid
+            if ((i + 1 - 46) % 101 == 0)
+            {
+                AnsiConsole.Write(canvas);
+                AnsiConsole.WriteLine();
+
+                AnsiConsole.Write($"Seconds elapsed: {i + 1}");
+
+                var key = Console.ReadKey(true).Key;
+
+                if (key is ConsoleKey.Enter)
+                {
+                    AnsiConsole.WriteLine();
+                    AnsiConsole.WriteLine();
+                    AnsiConsole.MarkupLine($"[green]Image at instant: [yellow]t={i + 1}s[/][/]");
+
+                    break;
+                }
+
+                AnsiConsole.Clear();
+            }
+        }
+    }
+
+    private List<Robot> ParseRobots()
+    {
+        var robots = new List<Robot>();
+
+        foreach (var line in Input.AsSpan().EnumerateLines())
+        {
+            var positionX = int.Parse(line[(line.IndexOf('=') + 1)..line.IndexOf(',')]);
+            var positionY = int.Parse(line[(line.IndexOf(',') + 1)..line.IndexOf(' ')]);
+
+            var velocityX = int.Parse(line[(line.LastIndexOf('=') + 1)..line.LastIndexOf(',')]);
+            var velocityY = int.Parse(line[(line.LastIndexOf(',') + 1)..]);
+
+            robots.Add(new Robot(new Point(positionX, positionY), new Point(velocityX, velocityY)));
+        }
+
+        return robots;
+    }
+
+    private class Robot(Point position, Point velocity)
+    {
+        public Point Position { get; set; } = position;
+        public Point Velocity { get; } = velocity;
+    }
+
+    private readonly record struct Point(int X, int Y)
+        : IAdditionOperators<Point, Point, Point>,
+            ISubtractionOperators<Point, Point, Point>,
+            IMultiplyOperators<Point, int, Point>
+    {
+        public static Point operator +(Point left, Point right)
+        {
+            return new Point(left.X + right.X, left.Y + right.Y);
+        }
+
+        public static Point operator -(Point left, Point right)
+        {
+            return new Point(left.X - right.X, left.Y - right.Y);
+        }
+
+        public static Point operator *(Point left, int right)
+        {
+            return new Point(left.X * right, left.Y * right);
+        }
+
+        public static Point operator *(int left, Point right)
+        {
+            return new Point(right.X * left, right.Y * left);
+        }
+
+        public static implicit operator Point((int X, int Y) point)
+            => new(point.X, point.Y);
+    }
+}