From c60fe81fb10281db5a75c538d097ead37465f6f1 Mon Sep 17 00:00:00 2001
From: Ben Harris <ben@tilde.team>
Date: Thu, 23 Nov 2023 11:35:08 -0500
Subject: [PATCH] 2016 day 2

---
 AOC.Common/Day.cs           |  4 +--
 AOC.Test/Test2016.cs        |  8 ++++++
 AOC2016/Day02.cs            | 54 ++++++++++++++++++++++++++++++++++---
 AOC2016/input2016/test02.in |  4 +++
 4 files changed, 65 insertions(+), 5 deletions(-)
 create mode 100644 AOC2016/input2016/test02.in

diff --git a/AOC.Common/Day.cs b/AOC.Common/Day.cs
index 011b05c..3ddb3e9 100644
--- a/AOC.Common/Day.cs
+++ b/AOC.Common/Day.cs
@@ -64,8 +64,8 @@ public abstract class Day(int year, int day, string puzzleName)
             throw new ApplicationException("no days found");
         }
 
-        UseTestInput = args is [_, "--test"] or ["--test", ..];
-        var verbose = args is [_, "--verbose"] or ["--verbose", ..];
+        UseTestInput = args.Contains("--test");
+        var verbose = args.Contains("--verbose");
 
         if (args.Length > 0 && int.TryParse(args[0], out var dayNum))
         {
diff --git a/AOC.Test/Test2016.cs b/AOC.Test/Test2016.cs
index 986d3f6..5e7bea5 100644
--- a/AOC.Test/Test2016.cs
+++ b/AOC.Test/Test2016.cs
@@ -7,8 +7,16 @@ public class Test2016
 {
     [DataTestMethod]
     [DataRow(typeof(Day01), "300", "159")]
+    [DataRow(typeof(Day02), "76792", "A7AC3")]
     public void CheckAllDays(Type dayType, string part1, string part2)
     {
         Common.CheckDay(dayType, part1, part2);
     }
+
+    [DataTestMethod]
+    [DataRow(typeof(Day02), "1985", "5DB3")]
+    public void CheckTestInputs(Type dayType, string part1, string part2)
+    {
+        Common.CheckDay(dayType, part1, part2, true);
+    }
 }
diff --git a/AOC2016/Day02.cs b/AOC2016/Day02.cs
index 174fe3c..a915a77 100644
--- a/AOC2016/Day02.cs
+++ b/AOC2016/Day02.cs
@@ -9,7 +9,55 @@ public sealed class Day02() : Day(2016, 2, "Puzzle Name")
     {
     }
 
-    public override object Part1() => "";
+    public override object Part1()
+    {
+        List<int> answer = new();
+        var location = (x: 1, y: 1);
 
-    public override object Part2() => "";
-}
+        foreach (var line in Input)
+        {
+            location = line.Aggregate(location, (c, instruction) => instruction switch
+            {
+                'U' => c with { y = c.y == 0 ? c.y : c.y - 1 },
+                'D' => c with { y = c.y == 2 ? c.y : c.y + 1 },
+                'L' => c with { x = c.x == 0 ? c.x : c.x - 1 },
+                'R' => c with { x = c.x == 2 ? c.x : c.x + 1 },
+                _ => throw new ArgumentException("invalid direction", nameof(instruction))
+            });
+
+            answer.Add(1 + location.x + location.y * 3);
+        }
+
+        return string.Join("", answer);
+    }
+
+    public override object Part2()
+    {
+        var keyPad = new[,]
+        {
+            { '\0', '\0', '1', '\0', '\0' },
+            { '\0', '2', '3', '4', '\0' },
+            { '5', '6', '7', '8', '9' },
+            { '\0', 'A', 'B', 'C', '\0' },
+            { '\0', '\0', 'D', '\0', '\0' },
+        };
+        var location = (x: 0, y: 2);
+        List<char> answer = new();
+
+        foreach (var line in Input)
+        {
+            location = line.Aggregate(location, (c, instruction) => instruction switch
+            {
+                'U' => c with { y = c.y == 0 || keyPad[c.y - 1, c.x] == '\0' ? c.y : c.y - 1 },
+                'D' => c with { y = c.y == 4 || keyPad[c.y + 1, c.x] == '\0' ? c.y : c.y + 1 },
+                'L' => c with { x = c.x == 0 || keyPad[c.y, c.x - 1] == '\0' ? c.x : c.x - 1 },
+                'R' => c with { x = c.x == 4 || keyPad[c.y, c.x + 1] == '\0' ? c.x : c.x + 1 },
+                _ => throw new ArgumentException("invalid direction", nameof(instruction))
+            });
+
+            answer.Add(keyPad[location.y, location.x]);
+        }
+
+        return string.Join("", answer);
+    }
+}
\ No newline at end of file
diff --git a/AOC2016/input2016/test02.in b/AOC2016/input2016/test02.in
new file mode 100644
index 0000000..5139196
--- /dev/null
+++ b/AOC2016/input2016/test02.in
@@ -0,0 +1,4 @@
+ULL
+RRDDD
+LURDL
+UUUUD