feat(2025-04): Add day 4

2026-07-13 03:03:46 +00:00 · 2025-12-04 12:49:03 +00:00
parent 4eaa778adb
commit af8d99e953
8 changed files with 594 additions and 2 deletions
@@ -0,0 +1,134 @@
+using AOC.Helpers;
+
+namespace AOC.Tests.Y2025;
+
+[TestFixture]
+[Parallelizable(ParallelScope.All)]
+public class Day04
+{
+    [SetUp]
+    public void Setup()
+    {
+        realData = File.ReadAllLines(Path.Combine(TestContext.CurrentContext.TestDirectory, "Y2025", "Data",
+            $"{GetThisClassName()}.dat"));
+    }
+
+    protected string GetThisClassName() { return GetType().Name; }
+    private string[] realData;
+
+    [TestCase(@"..@@.@@@@.
+@@@.@.@.@@
+@@@@@.@.@@
+@.@@@@..@.
+@@.@@@@.@@
+.@@@@@@@.@
+.@.@.@.@@@
+@.@@@.@@@@
+.@@@@@@@@.
+@.@.@@@.@.", 13)]
+    [TestCase(null, 1451)] // The actual answer
+    public void Part1(string? input, int? expected)
+    {
+        // string[] lines = input != null ? new[] { input } : realData;
+        string[] lines = input != null ? input.Split("\n") : realData;
+
+        char[,] array = TwoDimensionalArrays.Make2DArrayFromStringArray(lines);
+
+        int rollsOfPaperThatCanBeAccessed = 0;
+
+        foreach ((int row, int column, char value) in TwoDimensionalArrays.Cells(array))
+        {
+            if (value != '@')
+            {
+                continue;
+            }
+
+            List<(int, int)> positionsWherePaperExists =
+                TwoDimensionalArrays.CheckAllSurroundingCellsForCharacter(array, row, column, '@');
+
+            if (positionsWherePaperExists.Count < 4)
+            {
+                rollsOfPaperThatCanBeAccessed++;
+            }
+        }
+
+        int result = rollsOfPaperThatCanBeAccessed;
+
+        if (expected != null)
+        {
+            Assert.That(result, Is.EqualTo(expected.Value));
+        }
+
+        Console.WriteLine($"Part 1: {result}");
+    }
+
+    [TestCase(@"..@@.@@@@.
+@@@.@.@.@@
+@@@@@.@.@@
+@.@@@@..@.
+@@.@@@@.@@
+.@@@@@@@.@
+.@.@.@.@@@
+@.@@@.@@@@
+.@@@@@@@@.
+@.@.@@@.@.", 43)]
+    [TestCase(null, 8701)] // The actual answer
+    public void Part2(string? input, int? expected)
+    {
+        //string[] lines = input != null ? new[] { input } : realData;
+        string[] lines = input != null ? input.Split("\n") : realData;
+
+        char[,] array = TwoDimensionalArrays.Make2DArrayFromStringArray(lines);
+
+        int totalRollsOfPaperRemoved = 0;
+        int rollsOfPaperAccessed = 0;
+
+        bool continueLoop = true;
+
+        while (continueLoop)
+        {
+            List<(int, int)> positionsToRemovePaper = new();
+            foreach ((int row, int column, char value) in TwoDimensionalArrays.Cells(array))
+            {
+                if (value != '@')
+                {
+                    continue;
+                }
+
+                List<(int, int)> positionsWherePaperExists =
+                    TwoDimensionalArrays.CheckAllSurroundingCellsForCharacter(array, row, column, '@');
+
+                if (positionsWherePaperExists.Count < 4)
+                {
+                    totalRollsOfPaperRemoved++;
+                    rollsOfPaperAccessed++;
+                    positionsToRemovePaper.Add((row, column));
+                }
+            }
+
+            if (rollsOfPaperAccessed == 0)
+            {
+                continueLoop = false;
+            }
+
+            rollsOfPaperAccessed = 0;
+
+            // Remove each roll
+            foreach ((int, int) position in positionsToRemovePaper)
+            {
+                array[position.Item1, position.Item2] = 'x';
+            }
+
+            positionsToRemovePaper.Clear();
+        }
+
+        int result = totalRollsOfPaperRemoved;
+
+        if (expected != null)
+        {
+            Assert.That(result, Is.EqualTo(expected.Value));
+        }
+
+        Console.WriteLine($"Part 2: {result}");
+    }
+}