part1 (1439B)
1--- Day 2: Password Philosophy --- 2 3Your flight departs in a few days from the coastal airport; the easiest way down to the coast from here is via toboggan. 4 5The shopkeeper at the North Pole Toboggan Rental Shop is having a bad day. "Something's wrong with our computers; we can't log in!" You ask if you can take a look. 6 7Their password database seems to be a little corrupted: some of the passwords wouldn't have been allowed by the Official Toboggan Corporate Policy that was in effect when they were chosen. 8 9To try to debug the problem, they have created a list (your puzzle input) of [1m[37mpasswords[0m (according to the corrupted database) and [1m[37mthe corporate policy when that password was set[0m. 10 11For example, suppose you have the following list: 12 131-3 a: abcde 141-3 b: cdefg 152-9 c: ccccccccc 16 17Each line gives the password policy and then the password. The password policy indicates the lowest and highest number of times a given letter must appear for the password to be valid. For example, 1-3 a means that the password must contain a at least 1 time and at most 3 times. 18 19In the above example, [1m[37m2[0m passwords are valid. The middle password, cdefg, is not; it contains no instances of b, but needs at least 1. The first and third passwords are valid: they contain one a or nine c, both within the limits of their respective policies. 20 21[1m[37mHow many passwords are valid[0m according to their policies? 22 23