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