You arrive at the airport only to realize that you grabbed your North Pole Credentials instead of your passport. While these documents are extremely similar, North Pole Credentials aren't issued by a country and therefore aren't actually valid documentation for travel in most of the world.
It seems like you're not the only one having problems, though; a very long line has formed for the automatic passport scanners, and the delay could upset your travel itinerary.
Due to some questionable network security, you realize you might be able to solve both of these problems at the same time.
The automatic passport scanners are slow because they're having trouble detecting which passports have all required fields. The expected fields are as follows:
Passport data is validated in batch files (your puzzle input). Each passport is represented as a
key:value pairs separated by spaces or newlines. Passports are separated by blank
Here is an example batch file containing four passports:
ecl:gry pid:860033327 eyr:2020 hcl:#fffffd byr:1937 iyr:2017 cid:147 hgt:183cm iyr:2013 ecl:amb cid:350 eyr:2023 pid:028048884 hcl:#cfa07d byr:1929 hcl:#ae17e1 iyr:2013 eyr:2024 ecl:brn pid:760753108 byr:1931 hgt:179cm hcl:#cfa07d eyr:2025 pid:166559648 iyr:2011 ecl:brn hgt:59in
The first passport is valid - all eight fields are present. The second passport is
invalid - it is missing
hgt (the Height field).
The third passport is interesting; the only missing field is
cid, so it looks like data
from North Pole Credentials, not a passport at all! Surely, nobody would mind if you made the
system temporarily ignore missing
cid fields. Treat this "passport" as valid.
The fourth passport is missing two fields,
cid is fine, but missing
any other field is not, so this passport is invalid.
According to the above rules, your improved system would report
2 valid passports.
Count the number of valid passports - those that have all required fields. Treat
optional. In your batch file, how many passports are valid?
The line is moving more quickly now, but you overhear airport security talking about how passports with invalid data are getting through. Better add some data validation, quick!
You can continue to ignore the
cid field, but each other field has strict rules about what
values are valid for automatic validation:
byr(Birth Year) - four digits; at least
1920and at most
iyr(Issue Year) - four digits; at least
2010and at most
eyr(Expiration Year) - four digits; at least
2020and at most
hgt(Height) - a number followed by either
cm, the number must be at least
150and at most
in, the number must be at least
59and at most
hcl(Hair Color) - a
#followed by exactly six characters
ecl(Eye Color) - exactly one of:
pid(Passport ID) - a nine-digit number, including leading zeroes.
cid(Country ID) - ignored, missing or not.
Your job is to count the passports where all required fields are both present and valid according to the above rules. Here are some example values:
byr valid: 2002 byr invalid: 2003 hgt valid: 60in hgt valid: 190cm hgt invalid: 190in hgt invalid: 190 hcl valid: #123abc hcl invalid: #123abz hcl invalid: 123abc ecl valid: brn ecl invalid: wat pid valid: 000000001 pid invalid: 0123456789
Here are some invalid passports:
eyr:1972 cid:100 hcl:#18171d ecl:amb hgt:170 pid:186cm iyr:2018 byr:1926 iyr:2019 hcl:#602927 eyr:1967 hgt:170cm ecl:grn pid:012533040 byr:1946 hcl:dab227 iyr:2012 ecl:brn hgt:182cm pid:021572410 eyr:2020 byr:1992 cid:277 hgt:59cm ecl:zzz eyr:2038 hcl:74454a iyr:2023 pid:3556412378 byr:2007
Here are some valid passports:
pid:087499704 hgt:74in ecl:grn iyr:2012 eyr:2030 byr:1980 hcl:#623a2f eyr:2029 ecl:blu cid:129 byr:1989 iyr:2014 pid:896056539 hcl:#a97842 hgt:165cm hcl:#888785 hgt:164cm byr:2001 iyr:2015 cid:88 pid:545766238 ecl:hzl eyr:2022 iyr:2010 hgt:158cm hcl:#b6652a ecl:blu byr:1944 eyr:2021 pid:093154719
Count the number of valid passports - those that have all required fields and valid
values. Continue to treat
cid as optional. In your batch file, how many passports are