refactor: Move Input to the base class

AdventOfCode2025/Solutions/Day1.cs

@@ -2,18 +2,17 @@ using AdventOfCode2025.Inputs;
 
 namespace AdventOfCode2025.Solutions;
 
-public sealed class Day1 : Solution
+public sealed class Day1() : Solution(1)
 {
-    private readonly Input input = new(1);
     private const int MaxArrow = 100;
 
     public override string SolvePart1()
     {
         var arrow = 50;
         var zeroCounter = 0;
-        foreach (var line in input.Lines)
+        foreach (string line in Input.Lines)
         {
-            var number = int.Parse(line[1..]);
+            int number = int.Parse(line[1..]);
             arrow = line.First() switch
             {
                 'L' => arrow - number,
@@ -36,13 +35,13 @@ public sealed class Day1 : Solution
         var arrow = 50;
         var zeroCounter = 0;
 
-        foreach (var line in input.Lines)
+        foreach (string line in Input.Lines)
         {
-            var number = int.Parse(line[1..]);
+            int number = int.Parse(line[1..]);
             zeroCounter += number / MaxArrow;
-            var remainingNumber = number % MaxArrow;
+            int remainingNumber = number % MaxArrow;
 
-            var end = line.First() switch
+            int end = line.First() switch
             {
                 'L' => arrow - remainingNumber,
                 'R' => arrow + remainingNumber,

AdventOfCode2025/Solutions/Day2.cs

@@ -2,12 +2,11 @@ using AdventOfCode2025.Inputs;
 
 namespace AdventOfCode2025.Solutions;
 
-public class Day2 : Solution
+public class Day2() : Solution(2)
 {
-    private readonly Input input = new(2);
     public override string SolvePart1()
     {
-        return input.Lines
+        return Input.Lines
             .SelectMany(ToRanges)
             .Select(ToLimit)
             .SelectMany(GetIds)
@@ -18,7 +17,7 @@ public class Day2 : Solution
 
     public override string SolvePart2()
     {
-        return input.Lines
+        return Input.Lines
             .SelectMany(ToRanges)
             .Select(ToLimit)
             .SelectMany(GetIds)
@@ -31,8 +30,8 @@ public class Day2 : Solution
 
     private static IEnumerable<long> GetIds(string from, string to)
     {
-        var current = long.Parse(from);
+        long current = long.Parse(from);
-        var end = long.Parse(to);
+        long end = long.Parse(to);
         while (current <= end)
         {
             yield return current;
@@ -54,8 +53,8 @@ public class Day2 : Solution
                 continue;
             }
 
-            var testBlock = input[..subLength];
+            string testBlock = input[..subLength];
-            var theoreticalString = string.Concat(Enumerable.Repeat(testBlock, input.Length / subLength));
+            string theoreticalString = string.Concat(Enumerable.Repeat(testBlock, input.Length / subLength));
             if (theoreticalString == input)
             {
                 return true;
@@ -78,7 +77,7 @@ public class Day2 : Solution
         }
 
         var firstHalfIndex = 0;
-        var secondHalfIndex = input.Length / 2;
+        int secondHalfIndex = input.Length / 2;
         while (secondHalfIndex < input.Length)
         {
             if (input[firstHalfIndex] != input[secondHalfIndex])
@@ -95,7 +94,7 @@ public class Day2 : Solution
 
     private static (string from, string to) ToLimit(string range)
     {
-        var parts = range.Split('-');
+        string[] parts = range.Split('-');
         return (parts[0], parts[1]);
     }
 

AdventOfCode2025/Solutions/Day3.cs

@@ -2,13 +2,11 @@ using AdventOfCode2025.Inputs;
 
 namespace AdventOfCode2025.Solutions;
 
-public class Day3 : Solution
+public class Day3() : Solution(3)
 {
-    private readonly Input input = new(3);
+    public override string SolvePart1() => Input.Lines.Select(x => ParseLine(x, 2)).Sum().ToString();
 
-    public override string SolvePart1() => input.Lines.Select(x => ParseLine(x, 2)).Sum().ToString();
+    public override string SolvePart2() => Input.Lines.Select(x => ParseLine(x, 12)).Sum().ToString();
-
-    public override string SolvePart2() => input.Lines.Select(x => ParseLine(x, 12)).Sum().ToString();
 
     private static long GetLargestJolts(int[] bank, int numberOfJolts = 2)
     {

AdventOfCode2025/Solutions/Day4.cs

@@ -2,15 +2,14 @@ using AdventOfCode2025.Inputs;
 
 namespace AdventOfCode2025.Solutions;
 
-public class Day4 : Solution
+public class Day4() : Solution(4)
 {
-    private readonly Input input = new(4);
     private const char NoneChar = '.';
     private const char PaperChar = '@';
 
     public override string SolvePart1()
     {
-        var grid = PaddingField(input.Lines)
+        char[][] grid = PaddingField(Input.Lines)
             .Select(line => line.ToCharArray())
             .ToArray();
 
@@ -19,7 +18,7 @@ public class Day4 : Solution
 
     public override string SolvePart2()
     {
-        var grid = PaddingField(input.Lines)
+        char[][] grid = PaddingField(Input.Lines)
             .Select(line => line.ToCharArray())
             .ToArray();
         List<(int, int)> paperCanBeRemoved;
@@ -28,11 +27,12 @@ public class Day4 : Solution
         {
             paperCanBeRemoved = GetRemovablePaper(grid).ToList();
             paperCount += paperCanBeRemoved.Count;
-            foreach (var (row, col) in paperCanBeRemoved)
+            foreach ((int row, int col) in paperCanBeRemoved)
             {
                 grid[row][col] = NoneChar;
             }
-        } while (paperCanBeRemoved.Count > 0);
+        }
+        while (paperCanBeRemoved.Count > 0);
 
         return paperCount.ToString();
     }
@@ -59,12 +59,22 @@ public class Day4 : Solution
 
     private static bool HasMorePaperNeighborsAs(int x, int y, int threshold, char[][] grid)
     {
-        var directions = new (int dx, int dy)[] { (-1, -1), (0, -1), (1, -1), (-1, 0), (1, 0), (0, 1), (-1, 1), (1, 1) };
+        var directions = new (int dx, int dy)[]
-        var paperNeighbors = 0;
-        foreach (var (dx, dy) in directions)
         {
-            var nx = x + dx;
+            (-1, -1),
-            var ny = y + dy;
+            (0, -1),
+            (1, -1),
+            (-1, 0),
+            (1, 0),
+            (0, 1),
+            (-1, 1),
+            (1, 1)
+        };
+        var paperNeighbors = 0;
+        foreach ((int dx, int dy) in directions)
+        {
+            int nx = x + dx;
+            int ny = y + dy;
             if (nx < 0 || nx >= grid[0].Length || ny < 0 || ny >= grid.Length)
             {
                 continue;
@@ -88,7 +98,7 @@ public class Day4 : Solution
     private IEnumerable<string> PaddingField(IEnumerable<string> field)
     {
         List<string> lines = field.ToList();
-        var width = lines.First().Length;
+        int width = lines.First().Length;
         lines.Insert(0, new string(NoneChar, width));
         lines.Add(new string(NoneChar, width));
         return lines.Select(l => NoneChar + l + NoneChar);

AdventOfCode2025/Solutions/Day5.cs

@@ -2,12 +2,11 @@ using AdventOfCode2025.Inputs;
 
 namespace AdventOfCode2025.Solutions;
 
-public class Day5 : Solution
+public class Day5() : Solution(5)
 {
-    private readonly Input input = new(5);
     public override string SolvePart1()
     {
-        List<string> lines = input.Lines.ToList();
+        List<string> lines = Input.Lines.ToList();
         List<Range> freshRanges = GetFreshRanges(lines);
         int freshIngredients = lines[(freshRanges.Count + 1)..].Select(long.Parse).Count(id => IsFresh(id, freshRanges));
         return freshIngredients.ToString();
@@ -15,7 +14,7 @@ public class Day5 : Solution
 
     public override string SolvePart2()
     {
-        List<string> lines = input.Lines.ToList();
+        List<string> lines = Input.Lines.ToList();
         List<Range> ranges = GetFreshRanges(lines).OrderBy(x => x.From).ThenBy(x => x.To).ToList();
 
         var merged = new List<Range>();

AdventOfCode2025/Solutions/Day6.cs

@@ -2,10 +2,8 @@ using AdventOfCode2025.Inputs;
 
 namespace AdventOfCode2025.Solutions;
 
-public class Day6 : Solution
+public class Day6() : Solution(6)
 {
-    private readonly Input input = new(6);
-
     public override string SolvePart1()
     {
         (string[][] numberOfProblems, string[] arithmetics) = GetProblems();
@@ -51,7 +49,7 @@ public class Day6 : Solution
 
     private (string[][] numbersOfProblem, string[] arithmetic) GetProblems()
     {
-        List<string> lines = input.Lines.ToList();
+        List<string> lines = Input.Lines.ToList();
         int numberOfNumberRows = lines.Count - 1;
         var numbersOfProblem = new List<string[]>();
         var currentNumberRows = new string[numberOfNumberRows];

AdventOfCode2025/Solutions/Solution.cs

@@ -1,7 +1,10 @@
+using AdventOfCode2025.Inputs;
+
 namespace AdventOfCode2025.Solutions;
 
-public abstract class Solution
+public abstract class Solution(int day, int part = 1)
 {
+    protected readonly Input Input = new(day, part);
     public virtual string SolvePart1() => "Part1 is not solved";
     public virtual string SolvePart2() => "Part2 is not solved";
 }