Day 9: Encoding Error

Functions:

solve(puzzle_input, preamble_length)

Parse the data of the XMAS protocol, puzzle_input, and find a weakness.
solve(puzzle_input: List[int], preamble_length: int) → Optional[Tuple[int, int]][source]

Parse the data of the XMAS protocol, puzzle_input, and find a weakness.

Returns

offset of the number, first number after the preamble which uncovers the weakness

Requires

  • all(number >= 0 for number in puzzle_input)

  • len(puzzle_input) > preamble_length

Ensures
  • not result
or result[1]
not in [
    sum(t)
    for t in combinations(puzzle_input[result[0] - preamble_length : result[0]], 2)
]

  • result ⇒ result[1] in puzzle_input