Mercurial > hg > aoc
diff 2017/day04/problem @ 34:049fb8e56025
Add problem statements and inputs
author | Jordi Gutiérrez Hermoso <jordigh@octave.org> |
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date | Tue, 09 Jan 2018 21:51:44 -0500 |
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new file mode 100644 --- /dev/null +++ b/2017/day04/problem @@ -0,0 +1,49 @@ +--- 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 451. + +--- 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 223. + +Both parts of this puzzle are complete! They provide two gold stars: **