advent-of-code/2017/day/4/problem.txt

15 lines
602 B
Text
Raw Normal View History

2017-12-07 04:20:00 +00:00
--- 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?