From 48d6f0eaa3b976ff5244912363838f322f516c11 Mon Sep 17 00:00:00 2001
From: Ben Harris <ben@tilde.team>
Date: Fri, 11 Nov 2022 17:02:28 -0500
Subject: [PATCH] 2015 day 5

---
 AOC.Test/Test2015.cs        |  2 ++
 AOC2015/Day05.cs            | 34 ++++++++++++++++++++++++++++++----
 AOC2015/input2015/test05.in |  7 +++++++
 3 files changed, 39 insertions(+), 4 deletions(-)
 create mode 100644 AOC2015/input2015/test05.in

diff --git a/AOC.Test/Test2015.cs b/AOC.Test/Test2015.cs
index 08adb01..6843069 100644
--- a/AOC.Test/Test2015.cs
+++ b/AOC.Test/Test2015.cs
@@ -10,6 +10,7 @@ public class Test2015
     [DataRow(typeof(Day02),"1586300", "3737498")]
     [DataRow(typeof(Day03), "2081", "2341")]
     // [DataRow(typeof(Day04), "346386", "9958218")]
+    [DataRow(typeof(Day05), "258", "53")]
     public void TestAllDays(Type dayType, string part1, string part2)
     {
         Common.CheckDay(dayType, part1, part2);
@@ -20,6 +21,7 @@ public class Test2015
     [DataRow(typeof(Day02), "58", "34")]
     [DataRow(typeof(Day03), "2", "11")]
     // [DataRow(typeof(Day04), "609043", "6742839")]
+    [DataRow(typeof(Day05), "1", "1")]
     public void CheckTestInputs(Type dayType, string part1, string part2)
     {
         Day.UseTestInput = true;
diff --git a/AOC2015/Day05.cs b/AOC2015/Day05.cs
index 687c5f0..00822ff 100644
--- a/AOC2015/Day05.cs
+++ b/AOC2015/Day05.cs
@@ -3,13 +3,39 @@
 /// <summary>
 /// Day 5: <see href="https://adventofcode.com/2015/day/5"/>
 /// </summary>
-public sealed class Day05 : Day
+public sealed partial class Day05 : Day
 {
-    public Day05() : base(2015, 5, "Puzzle Name")
+    private readonly List<string> _strings;
+    private static readonly List<char> Vowels = new() { 'a', 'e', 'i', 'o', 'u' };
+    
+    [GeneratedRegex(@"(.)\1")]
+    private static partial Regex DoubleLetter();
+
+    [GeneratedRegex(@"(.).\1")]
+    private static partial Regex LetterSandwich();
+
+    [GeneratedRegex(@"(..).*\1")]
+    private static partial Regex TwoPairs();
+
+    public Day05() : base(2015, 5, "Doesn't He Have Intern-Elves For This?")
     {
+        _strings = Input.Where(line => !string.IsNullOrEmpty(line)).ToList();
     }
 
-    public override object Part1() => "";
+    public override object Part1() =>
+        _strings.Count(s =>
+        {
+            // bad substrings
+            if (s.Contains("ab") || s.Contains("cd") || s.Contains("pq") || s.Contains("xy"))
+                return false;
 
-    public override object Part2() => "";
+            // must have at least 3 vowels
+            if (s.Count(c => Vowels.Contains(c)) < 3) return false;
+
+            // must have a double-letter somewhere
+            return DoubleLetter().Matches(s).Count >= 1;
+        });
+
+    public override object Part2() =>
+        _strings.Count(s => LetterSandwich().Matches(s).Count >= 1 && TwoPairs().Matches(s).Count == 1);
 }
diff --git a/AOC2015/input2015/test05.in b/AOC2015/input2015/test05.in
new file mode 100644
index 0000000..e7ab0e9
--- /dev/null
+++ b/AOC2015/input2015/test05.in
@@ -0,0 +1,7 @@
+ugknbfddgicrmopn
+jchzalrnumimnmhp
+haegwjzuvuyypxyu
+dvszwmarrgswjxmb
+qjhvhtzxzqqjkmpb
+uurcxstgmygtbstg
+ieodomkazucvgmuy