2016 day 6

AOC.Test/Test2016.cs

@@ -11,13 +11,14 @@ public class Test2016
     [DataRow(typeof(Day03), "993", "1849")]
     [DataRow(typeof(Day04), "361724", "482")]
     //[DataRow(typeof(Day05), "F77A0E6E", "999828EC")] // TODO: optimize day 5
+    [DataRow(typeof(Day06), "gyvwpxaz", "jucfoary")]
     public void CheckAllDays(Type dayType, string part1, string part2) =>
         Common.CheckDay(dayType, part1, part2);
 
     [DataTestMethod]
     [DataRow(typeof(Day02), "1985", "5DB3")]
     //[DataRow(typeof(Day05), "18F47A30", "05ACE8E3")]
-    [DataRow(typeof(Day06), "easter", "")]
+    [DataRow(typeof(Day06), "easter", "advent")]
     public void CheckTestInputs(Type dayType, string part1, string part2) =>
         Common.CheckDay(dayType, part1, part2, true);
 }

AOC2016/Day06.cs

@@ -5,11 +5,44 @@ namespace AOC2016;
 /// </summary>
 public sealed class Day06() : Day(2016, 6, "Signals and Noise")
 {
+    private List<string> _input;
+
     public override void ProcessInput()
     {
+        _input = Input.ToList();
     }
 
-    public override object Part1() => "";
+    public override object Part1()
+    {
+        var answer = new char[_input[0].Length];
 
-    public override object Part2() => "";
-}
+        for (var i = 0; i < _input[0].Length; i++)
+        {
+            answer[i] = _input
+                .Select(l => l[i])
+                .GroupBy(c => c)
+                .OrderByDescending(g => g.Count())
+                .Select(g => g.Key)
+                .First();
+        }
+
+        return new string(answer);
+    }
+
+    public override object Part2()
+    {
+        var answer = new char[_input[0].Length];
+
+        for (var i = 0; i < _input[0].Length; i++)
+        {
+            answer[i] = _input
+                .Select(l => l[i])
+                .GroupBy(c => c)
+                .OrderBy(g => g.Count())
+                .Select(g => g.Key)
+                .First();
+        }
+
+        return new string(answer);
+    }
+}