day 10!

10/a.py

@@ -0,0 +1,59 @@
+from collections import Counter
+import itertools
+import math
+
+lines = { int(x) for x in open('input').read().splitlines() }
+lines.add(0)
+
+def a(transformers):
+    v = 0
+    dv = [3] #Always a 3 v transform at the end
+    while v < max(transformers):
+        v_ = min(set(range(v+1,v+4)).intersection(transformers))
+        dv.append(v_ - v)
+        v = v_
+        # print(dv)
+
+    count = dict(Counter(dv))
+    return count[3]*count[1]
+
+# print(lines)
+
+# This is a recursive solution. IT works but it'll take an eternity to go through the whole list of transformers.
+# Instead, we split 
+def b(c, v, transformers):
+    for v_ in set(range(v+1,v+4)).intersection(lines):
+        # print(v_)
+        if v_ == max(transformers):
+            c += 1
+        else:
+            c = b(c, v_, transformers)
+    return c
+# print(b(0, 0, lines)) #Does not work for big sets!
+# print(b(0, 1, {1, 2, 3, 4}))
+# print(b(0, 7, {7, 8, 9, 10, 11}))
+
+def b_optimized(transformers):
+    rel = { v: set(range(v+1,v+4)).intersection(transformers) for v in transformers }
+    rel.pop(max(transformers))
+    # print(rel)
+    # print({ x if (vf in rel[x]) else None for x in rel }.intersection(transformers))
+    gaps = { list(rel[x])[0] if (len(rel[x]) == 1) else None for x in rel }.intersection(transformers)
+    gaps.add(list(rel)[0])
+    gaps = sorted(gaps)
+    # print(gaps)
+
+    idx = 0
+    C = 1
+    while idx+1 < len(gaps):
+        s = sorted(set(range(gaps[idx],gaps[idx+1]+1)).intersection(transformers))
+        # print(s)
+        if len(s) > 2:
+            C *= b(0, list(s)[0], s)
+            # print(C, b(0, list(s)[0], s))
+
+        idx += 1
+    return C
+
+print(a(lines))
+print(b_optimized(lines))