d06.py

import re
from math import ceil, floor, sqrt

print('Day 6 of Advent of Code!')


def parse_without_kerning(data):
    times, distances = data.split('\n')
    race_times = [int(race_time) for race_time in list(re.findall(r'\d+', times))]
    race_distances = [int(race_distance) for race_distance in list(re.findall(r'\d+', distances))]

    return zip(race_times, race_distances)


def parse_with_kerning(data):
    times, distances = data.split('\n')
    race_times = "".join(list(re.findall(r'\d+', times)))
    race_distances = "".join(list(re.findall(r'\d+', distances)))

    return int(race_times), int(race_distances)


def solve_race(race):
    '''Solving (race_time - x) * x > max_distance for minimum and maximum integer solution.'''
    a = -1
    b = race[0]
    c = -race[1]
    delta = b**2 - 4 * a * c

    lo = (-b + sqrt(delta)) / 2 * a
    hi = (-b - sqrt(delta)) / 2 * a

    discrete_lo = ceil(lo) if ceil(lo) != lo else lo + 1
    discrete_hi = floor(hi) if floor(hi) != hi else hi - 1

    return int(discrete_hi - discrete_lo + 1)


def solve_multiple_races(data):
    acc = 1
    for race in parse_without_kerning(data):
        acc *= solve_race(race)
    return acc


TEST_DATA = '''Time:      7  15   30
Distance:  9  40  200'''


print('Testing...')
print('Part 1:', solve_multiple_races(TEST_DATA) == 288)
print('Part 2:', solve_race(parse_with_kerning(TEST_DATA)) == 71503)

with open('inp', mode='r', encoding='utf-8') as inp:
    print('Solution...')
    actual_data = inp.read()
    print('Part 1:', solve_multiple_races(actual_data))
    print('Part 2:', solve_race(parse_with_kerning(actual_data)))