Advent of Code 2017

December 4th

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?

In [1]:
from notebook_preamble import J, V, define

I'll assume the input is a Joy sequence of sequences of integers.

[[5 1 9 5]
 [7 5 4 3]
 [2 4 6 8]]

So, obviously, the initial form will be a step function:

AoC2017.4 == 0 swap [F +] step
F == [size] [unique size] cleave =

The step_zero combinator includes the 0 swap that would normally open one of these definitions:

In [2]:
J('[step_zero] help')

==== Help on step_zero ====

0 roll> step

---- end (step_zero)



AoC2017.4 == [F +] step_zero
In [3]:
define('AoC2017.4 [[size] [unique size] cleave = +] step_zero')
In [4]:
J('''

[[5 1 9 5]
 [7 5 4 3]
 [2 4 6 8]] AoC2017.4

''')

2