2017 Day 4 Complete!

2017/day04/problem

@@ -0,0 +1,74 @@
+Advent of Code
+
+--- Day 4: High-Entropy Passphrases ---
+
+   A new system policy has been put in place that requires all
+   accounts to use a passphrase instead of simply a password. A
+   passphrase consists of a series of words (lowercase letters)
+   separated by spaces.
+
+   To ensure security, a valid passphrase must contain no
+   duplicate words.
+
+   For example:
+
+     * aa bb cc dd ee is valid.
+     * aa bb cc dd aa is not valid - the word aa appears more
+       than once.
+     * aa bb cc dd aaa is valid - aa and aaa count as different
+       words.
+
+   The system's full passphrase list is available as your
+   puzzle input. How many passphrases are valid?
+
+   Your puzzle answer was ____.
+
+--- Part Two ---
+
+   For added security, yet another system policy has been put
+   in place. Now, a valid passphrase must contain no two words
+   that are anagrams of each other - that is, a passphrase is
+   invalid if any word's letters can be rearranged to form any
+   other word in the passphrase.
+
+   For example:
+
+     * abcde fghij is a valid passphrase.
+     * abcde xyz ecdab is not valid - the letters from the
+       third word can be rearranged to form the first word.
+     * a ab abc abd abf abj is a valid passphrase, because all
+       letters need to be used when forming another word.
+     * iiii oiii ooii oooi oooo is valid.
+     * oiii ioii iioi iiio is not valid - any of these words
+       can be rearranged to form any other word.
+
+   Under this new system policy, how many passphrases are
+   valid?
+
+   Your puzzle answer was ____.
+
+   Both parts of this puzzle are complete! They provide two
+   gold stars: **
+
+   At this point, you should return to your advent calendar and
+   try another puzzle.
+
+   If you still want to see it, you can get your puzzle input.
+
+References
+
+   Visible links
+   . http://adventofcode.com/
+   . http://adventofcode.com/2017/about
+   . http://adventofcode.com/2017/support
+   . http://adventofcode.com/2017/events
+   . http://adventofcode.com/2017/settings
+   . http://adventofcode.com/2017/auth/logout
+   . http://adventofcode.com/2017
+   . http://adventofcode.com/2017
+   . http://adventofcode.com/2017/leaderboard
+   . http://adventofcode.com/2017/stats
+   . http://adventofcode.com/2017/sponsors
+   . http://adventofcode.com/2017/sponsors
+   . http://adventofcode.com/2017
+   . http://adventofcode.com/2017/day/4/input