Part 2, works with example but fails live

tetsuo13 · Jan 4, 2024 · 81aff12 · 81aff12
1 parent fcfb259
commit 81aff12
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Showing 2 changed files with 35 additions and 9 deletions.
diff --git a/AdventOfCode/Calendar/2023/Day04/Solution.cs b/AdventOfCode/Calendar/2023/Day04/Solution.cs
@@ -2,23 +2,46 @@
 
 internal class Solution : BaseSolution
 {
+    private class Scratchcard
+    {
+        public IEnumerable<int> WinningNumbers { get; set; } = Enumerable.Empty<int>();
+        public IEnumerable<int> MyNumbers { get; set; } = Enumerable.Empty<int>();
+        public int Worth => (int)Math.Pow(2, WinningNumbers.Count() - 1);
+    }
+
     public override async Task<int> Run(RunMode runMode)
     {
         return runMode switch
         {
             RunMode.PartOne => await TotalPoints(),
+            RunMode.PartTwo => await TotalScratchcards(),
             _ => throw new ArgumentOutOfRangeException(nameof(runMode))
         };
     }
 
-    private class Scratchcard
+    private async Task<int> TotalPoints()
     {
-        public IEnumerable<int> WinningNumbers { get; set; } = Enumerable.Empty<int>();
-        public IEnumerable<int> MyNumbers { get; set; } = Enumerable.Empty<int>();
-        public int Worth => (int)Math.Pow(2, WinningNumbers.Count() - 1);
+        var scratchcards = await CountCards();
+        return scratchcards.Sum(x => x.Worth);
     }
 
-    private async Task<int> TotalPoints()
+    private async Task<int> TotalScratchcards()
+    {
+        var scratchcards = await CountCards();
+        var counts = Enumerable.Repeat(1, scratchcards.Count).ToArray();
+
+        for (var i = 0; i < scratchcards.Count; i++)
+        {
+            for (var j = 1; j <= scratchcards[i].WinningNumbers.Count(); j++)
+            {
+                counts[i + j] += counts[i];
+            }
+        }
+
+        return counts.Sum();
+    }
+
+    private async Task<List<Scratchcard>> CountCards()
     {
         var cards = await ReadInput();
         var scratchcards = new List<Scratchcard>();
@@ -39,10 +62,12 @@ private async Task<int> TotalPoints()
             scratchcards.Add(scratchcard);
         }
 
-        return scratchcards.Sum(x => x.Worth);
-
+        return scratchcards;
     }
 
-    private static IEnumerable<int> ParseOutNumbers(string s) =>
-        s.Split(' ', StringSplitOptions.RemoveEmptyEntries).Select(int.Parse);
+    private static IEnumerable<int> ParseOutNumbers(string s)
+    {
+        return s.Split(' ', StringSplitOptions.RemoveEmptyEntries)
+            .Select(int.Parse);
+    }
 }
diff --git a/AdventOfCode/Calendar/2023/Day04/SolutionTests.cs b/AdventOfCode/Calendar/2023/Day04/SolutionTests.cs
@@ -11,6 +11,7 @@ private class TestSolution(string[] inputLines) : Solution
 
     [Theory]
     [InlineData(RunMode.PartOne, 13)]
+    [InlineData(RunMode.PartTwo, 30)]
     public async Task Example(RunMode runMode, int expected)
     {
         string[] input =