Day 2 - Advent of Code 2024

""" day_02_01.py """

# usage: python3 day_02_01.py < input

import sys


def values(text):
    """ report values """
    return list(map(int, text.split()))


def safe(nums):
    """ are report values safe by puzzle description """
    diffs = [i - j for i, j in zip(nums, nums[1:])]
    if 0 in diffs:
        return False
    if max(map(abs, diffs)) > 3:
        return False
    if abs(sum(1 if d > 0 else -1 for d in diffs)) < len(diffs):
        return False
    return True


with sys.stdin as infile:
    print(sum(safe(values(report)) for report in infile))

""" day_02_02.py """

# usage: python3 day_02_02.py < input

import sys


def values(text):
    """ report values """
    return list(map(int, text.split()))


def safe(nums):
    """ are report values safe by puzzle description """
    diffs = [i - j for i, j in zip(nums, nums[1:])]
    if 0 in diffs:
        return False
    if max(map(abs, diffs)) > 3:
        return False
    if abs(sum(1 if d > 0 else -1 for d in diffs)) < len(diffs):
        return False
    return True


def dampener_safe(nums):
    """ a dampened report drops one value """
    return any(safe(nums[0:i] + nums[i + 1:]) for i in range(len(nums)))


with sys.stdin as infile:
    print(sum(dampener_safe(values(report)) for report in infile))