Day 23 Part 2

KaterynaKateryna · Dec 23, 2024 · 461b201 · 461b201
1 parent a10c3a1
commit 461b201
Showing 1 changed file with 67 additions and 25 deletions.
diff --git a/AdventOfCode/Day23.cs b/AdventOfCode/Day23.cs
@@ -1,34 +1,14 @@
-namespace AdventOfCode;
+using System.Text.RegularExpressions;
+
+namespace AdventOfCode;
 
 public class Day23 : BaseDay
 {
     public override ValueTask<string> Solve_1()
     {
         string[] lines = File.ReadAllLines(InputFilePath);
-
-        HashSet<string> groups = new HashSet<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]}");
-                    }
-                }
-            }
-        }
+        HashSet<string> groups = GetSetsOfThree(lines, dictionary);
 
         int res = groups.Count(g => g.Split(",").Any(x => x.StartsWith("t")));
 
@@ -37,7 +17,17 @@ public override ValueTask<string> Solve_1()
 
     public override ValueTask<string> Solve_2()
     {
-        return new ("");
+        string[] lines = File.ReadAllLines(InputFilePath);
+        Dictionary<string, List<string>> dictionary = ToDictionary(lines);
+        HashSet<string> groups = GetSetsOfThree(lines, dictionary);
+
+        while (groups.Count != 1)
+        {
+            groups = GetGroupsPlusOne(groups, dictionary);
+            Console.WriteLine(groups.Count);
+        }
+
+        return new (groups.Single().ToString());
     }
 
     private Dictionary<string, List<string>> ToDictionary(string[] lines)
@@ -61,4 +51,56 @@ private Dictionary<string, List<string>> ToDictionary(string[] lines)
 
         return result;
     }
+
+    private HashSet<string> GetSetsOfThree(string[] lines, Dictionary<string, List<string>> dictionary)
+    {
+        HashSet<string> groups = new HashSet<string>();
+
+        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]}");
+                    }
+                }
+            }
+        }
+        return groups;
+    }
+
+    private HashSet<string> GetGroupsPlusOne(HashSet<string> groups, Dictionary<string, List<string>> dictionary)
+    {
+        HashSet<string> groupsPlusOne = new HashSet<string>();
+        foreach (var group in groups)
+        {
+            List<string> computers = group.Split(",").ToList();
+            foreach (var computer in dictionary.Keys)
+            {
+                if (computers.Contains(computer))
+                {
+                    continue;
+                }
+                int intersect = dictionary[computer].Intersect(computers).Count();
+                if (intersect == computers.Count)
+                {
+                    var newGroup = computers.Concat(new List<string> { computer });
+                    newGroup = newGroup.OrderBy(x => x).ToList();
+                    groupsPlusOne.Add(string.Join(",", newGroup));
+                }
+            }
+        }
+
+        return groupsPlusOne;
+    }
 }