Day 23 part 1

AdventOfCode/Day23.cs

@@ -0,0 +1,64 @@
+namespace AdventOfCode;
+
+public class Day23 : BaseDay
+{
+    public override ValueTask<string> Solve_1()
+    {
+        string[] lines = File.ReadAllLines(InputFilePath);
+
+        HashSet<(string, string, string)> groups = new HashSet<(string, string, string)>();
+        Dictionary<string, List<string>> dictionary = ToDictionary(lines);
+
+        foreach (var kv in dictionary)
+        {
+            string computer1 = kv.Key;
+            if (kv.Value.Count < 2)
+            {
+                continue;
+            }
+            for (int i = 0; i < kv.Value.Count - 1; ++i)
+            {
+                for (int j = i + 1; j < kv.Value.Count; ++j)
+                {
+                    if (dictionary[kv.Value[i]].Contains(kv.Value[j]))
+                    {
+                        var group = new List<string> { computer1, kv.Value[i], kv.Value[j] };
+                        group = group.OrderBy(x => x).ToList();
+                        groups.Add((group[0], group[1], group[2]));
+                    }
+                }
+            }
+        }
+
+        int res = groups.Count(g => g.Item1.StartsWith("t") || g.Item2.StartsWith("t") || g.Item3.StartsWith("t"));
+
+        return new (res.ToString());
+    }
+
+    public override ValueTask<string> Solve_2()
+    {
+        return new ("");
+    }
+
+    private Dictionary<string, List<string>> ToDictionary(string[] lines)
+    {
+        Dictionary<string, List<string>> result = new Dictionary<string, List<string>>();
+
+        foreach (string line in lines)
+        {
+            string[] computers = line.Split("-", StringSplitOptions.RemoveEmptyEntries);
+
+            if (!result.TryAdd(computers[0], new List<string>() { computers[1] }))
+            {
+                result[computers[0]].Add(computers[1]);
+            }
+
+            if (!result.TryAdd(computers[1], new List<string>() { computers[0] }))
+            {
+                result[computers[1]].Add(computers[0]);
+            }
+        }
+
+        return result;
+    }
+}