2015 day 11

2015/11/passgen.py

@@ -0,0 +1,57 @@
+#!/usr/bin/env python3
+from string import ascii_lowercase
+from baseconv import BaseConverter
+
+
+class IncrementalPasswordGenerator(object):
+
+    def __init__(self,
+                 initial='abcdefgh',
+                 alphabet=ascii_lowercase,
+                 ignored='iol'):
+        self.alphabet = alphabet.translate({ord(c): None for c in ignored})
+        self.password_length = len(initial)
+        self.converter = BaseConverter(self.alphabet)
+        self.current = int(self.converter.decode(initial))
+        
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        self.current += 1
+        self.encoded = self.converter.encode(self.current).rjust(self.password_length, self.alphabet[0])
+        return self.encoded
+
+
+class SantaPasswordGenerator(IncrementalPasswordGenerator):
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.pairs = {letter * 2 for letter in self.alphabet}
+        self.suites = {self.alphabet[i:i+3] for i in range(len(self.alphabet) - 2)}
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        super().__next__()
+        while not self.is_valid:
+            super().__next__()
+        return self.encoded
+
+    @property
+    def is_valid(self):
+        try:
+            pairs_gen = filter(lambda pair: pair in self.encoded, self.pairs)
+            next(pairs_gen)
+            next(pairs_gen)
+            assert any(suite in self.encoded for suite in self.suites)
+            return True
+        except (AssertionError, StopIteration):
+            return False
+
+
+if __name__ == '__main__':
+    import sys
+    gen = SantaPasswordGenerator(sys.argv[1])
+    print(next(gen), next(gen))

2015/11/requirements.txt

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+python-baseconv>=1.2