AoC 2020 (Day 2)

2.rb

input = [
"1-3 a: abcde",
"1-3 b: cdefg",
"2-9 c: ccccccccc"
]

def parse(str)
  str.match(/(?<min>\d+)-(?<max>\d+) (?<char>\S): (?<testcase>\S+)/)
end

def validate(ipt)
  info = parse(ipt)
  min, max, char, testcase = info.values_at(:min, :max, :char, :testcase)
  count = testcase.count(char)
  count <= max.to_i && count >= min.to_i
end

input.select { |ipt| validate(ipt) === true }.count