Day 14 (ugly)

Day13.cs

@@ -1,4 +1,4 @@
-#define Day13
+// #define Day13
 #if Day13
 using System.Text.RegularExpressions;
 

Day14.cs

@@ -0,0 +1,78 @@
+#define Day14
+#if Day14
+using System.Text.RegularExpressions;
+using AoC2021;
+var text = File.ReadAllText("day14/input").Split("\n\n");
+var startOne = text[0].Select(x => x).ToList();
+var startTwo = startOne.ToList();
+
+var reg = new Regex(@"(?<a>\w)(?<b>\w) -> (?<res>\w)");
+var rules = reg.Matches(text[1]).Select(m => new Rule(new Pair(m.Groups["a"].Value[0], m.Groups["b"].Value[0]), m.Groups["res"].Value[0])).ToDictionary(x => x.p, x=> x.res);
+
+// for (var i = 0; i < 10; i++) {
+//     var next = new List<char>();
+//     for (int pos = 1; pos < startOne.Count; pos++) {
+//         var res = rules[new Pair(startOne[pos - 1], startOne[pos])];
+//         next.Add(startOne[pos - 1]);
+//         next.Add(res);
+//     }
+//     next.Add(startOne.Last());
+//     startOne = next;
+// }
+//
+// var charCountPartOne = startOne.GroupBy(s => s).ToDictionary(g => g.Key, g => g.LongCount());
+// Console.WriteLine(charCountPartOne.Values.Max() - charCountPartOne.Values.Min());
+//
+// var charCountPartTwo = rules.Keys.SelectMany(r => new List<char>(){r.a, r.b}).Distinct().ToDictionary(x => x, _ => 0L);
+int maxDepth = 40;
+
+var finalCount = new Dictionary<char, long>();
+var save = new Dictionary<AsKey, Dictionary<char, long>>();
+
+Dictionary<char, long> Bla(Pair cur, int depth) {
+    var curKey = new AsKey(cur, depth);
+    if (save.ContainsKey(curKey)) {
+        return save[curKey];
+    }
+    if (depth <= 0) {
+        return new Dictionary<char, long>() { {cur.a, 1} };
+    }
+
+    var c = rules[cur];
+    var first = Bla(new Pair(cur.a, c), depth - 1);
+    var second = Bla(new Pair(c, cur.b), depth - 1);
+
+    var merged = Merge(first, second);
+    save[curKey] = merged.ToDictionary(x => x.Key, x => x.Value);
+
+    return merged;
+}
+
+Dictionary<char, long> Merge(Dictionary<char, long> a, Dictionary<char, long> b) {
+    var merged = new Dictionary<char, long>();
+    foreach (var k in a.Keys) {
+        merged.Add(k, a[k]);
+    }
+    foreach (var k in b.Keys) {
+        if (merged.ContainsKey(k)) {
+            merged[k] += b[k];
+        } else {
+            merged[k] = b[k];
+        }
+    }
+
+    return merged;
+}
+
+for (int pos = 1; pos < startTwo.Count; pos++) {
+    var countBla = Bla(new Pair(startTwo[pos - 1], startTwo[pos]), maxDepth);
+    finalCount = Merge(finalCount, countBla);
+}
+finalCount[startTwo.Last()]++;
+
+Console.WriteLine(finalCount.Values.Max() - finalCount.Values.Min());
+
+record AsKey(Pair p, int depth);
+record Rule(Pair p, char res);
+record Pair(char a, char b);
+#endif

day14/input

@@ -0,0 +1,102 @@
+PSVVKKCNBPNBBHNSFKBO
+
+CF -> H
+PP -> H
+SP -> V
+NO -> C
+SF -> F
+FS -> H
+OF -> P
+PN -> B
+SH -> V
+BO -> K
+ON -> V
+VP -> S
+HN -> B
+PS -> P
+FV -> H
+NC -> N
+FN -> S
+PF -> F
+BF -> F
+NB -> O
+HS -> C
+SC -> V
+PC -> K
+KF -> K
+HC -> C
+OK -> H
+KS -> P
+VF -> C
+NV -> S
+KK -> F
+HV -> H
+SV -> V
+KC -> N
+HF -> P
+SN -> F
+VS -> P
+VN -> F
+VH -> C
+OB -> K
+VV -> O
+VC -> O
+KP -> V
+OP -> C
+HO -> S
+NP -> K
+HB -> C
+CS -> S
+OO -> S
+CV -> K
+BS -> F
+BH -> P
+HP -> P
+PK -> B
+BB -> H
+PV -> N
+VO -> P
+SS -> B
+CC -> F
+BC -> V
+FF -> S
+HK -> V
+OH -> N
+BV -> C
+CP -> F
+KN -> K
+NN -> S
+FB -> F
+PH -> O
+FH -> N
+FK -> P
+CK -> V
+CN -> S
+BP -> K
+CH -> F
+FP -> K
+HH -> N
+NF -> C
+VB -> B
+FO -> N
+PB -> C
+KH -> K
+PO -> K
+OV -> F
+NH -> H
+KV -> B
+OS -> K
+OC -> K
+FC -> H
+SO -> H
+KO -> P
+NS -> F
+CB -> C
+CO -> F
+KB -> V
+BK -> K
+NK -> O
+SK -> C
+SB -> B
+VK -> O
+BN -> H