Day 14

14.py

@@ -0,0 +1,33 @@
+#!/usr/bin/python3
+
+import functools
+import hashlib
+import itertools
+import re
+
+salt = 'cuanljph'
+
+
+@functools.lru_cache(maxsize=1024)
+def md5(index):
+	return hashlib.md5((salt + str(index)).encode('UTF-8')).hexdigest()
+
+
+@functools.lru_cache(maxsize=1024)
+def stretched(index):
+	key = salt + str(index)
+	for _ in range(2017): key = hashlib.md5(key.encode('UTF-8')).hexdigest()
+	return key
+
+
+@functools.lru_cache(maxsize=1024)
+def trip(index, fn):
+	return tripmatcher.search(fn(index))
+
+tripmatcher = re.compile(r'(.)\1{2}')
+matches = lambda fn: ((i, fn(i)) for i in itertools.count()
+	          if trip(i, fn) and any(trip(i, fn).group(1) * 5 in fn(n)
+	          	                     for n in range(i + 1, i + 1000)))
+ 
+print("Part one: %s" % next(itertools.islice(matches(md5), 63, 64))[0])
+print("Part two: %s" % next(itertools.islice(matches(stretched), 63, 64))[0])