5 To ensure security, a valid passphrase must contain no duplicate words.
9 * aa bb cc dd ee is valid.
10 * aa bb cc dd aa is not valid - the word aa appears more than once.
11 * aa bb cc dd aaa is valid - aa and aaa count as different words.
13 The system's full passphrase list is available as your puzzle input. How many passphrases are valid?
17 from notebook_preamble import J, V, define
20 I'll assume the input is a Joy sequence of sequences of integers.
26 So, obviously, the initial form will be a `step` function:
28 AoC2017.4 == 0 swap [F +] step
31 F == [size] [unique size] cleave =
34 The `step_zero` combinator includes the `0 swap` that would normally open one of these definitions:
45 AoC2017.4 == [F +] step_zero
49 define('AoC2017.4 == [[size] [unique size] cleave = +] step_zero')