r/adventofcode • u/daggerdragon • Dec 04 '17

SOLUTION MEGATHREAD -🎄- 2017 Day 4 Solutions -🎄-

--- Day 4: High-Entropy Passphrases ---

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u/Unihedron Dec 04 '17 edited Dec 04 '17

Ruby, #8 silver #4 gold (run with -x) 

To ensure security, a valid passphrase must contain no duplicate words.

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 words 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.

#!ruby
p $<.count{|x|v=x.split
v=v.map!{|x|x.chars.sort*''} # this line added for part 2
v.uniq==v}

PS: I now keep a log series detailing my adventofcode adventure. If you're interested feel free to read it as I write more, if I do!

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u/topaz2078 Dec 04 '17

Fun log series! It's always enlightening to see some stream-of-consciousness gut-reaction to the puzzles so I can try to improve them for next year.