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import gleam/io
import gleam/list
import gleam/string
import gleam/bool
import ext/resultx
import util/input_util
import util/parser as p
type Policy {
Policy(min: Int, max: Int, grapheme: String)
}
type Line {
Line(policy: Policy, password: String)
}
fn is_line_valid1(line: Line) -> Bool {
line.password
|> string.to_graphemes
|> list.filter(for: fn(g) { g == line.policy.grapheme })
|> list.length
|> fn(l) { line.policy.min <= l && l <= line.policy.max }
}
fn is_line_valid2(line: Line) -> Bool {
let graphemes = string.to_graphemes(line.password)
let grapheme_matches = fn(idx) {
list.at(in: graphemes, get: idx - 1)
|> resultx.force_unwrap == line.policy.grapheme
}
bool.exclusive_or(
grapheme_matches(line.policy.min),
grapheme_matches(line.policy.max),
)
}
fn parse_line(string: String) -> Line {
let policy_parser =
p.int()
|> p.then_skip(p.grapheme_literal("-"))
|> p.then(p.int())
|> p.then_skip(p.grapheme_literal(" "))
|> p.then_third(p.any_grapheme())
|> p.then_skip(p.string_literal(": "))
|> p.map3(with: fn(min, max, grapheme) { Policy(min, max, grapheme) })
|> p.labeled(with: "policy")
let password_parser = p.labeled(p.any_string(), with: "password")
let line_parser =
policy_parser
|> p.then(password_parser)
|> p.map2(fn(policy, password) { Line(policy, password) })
|> p.labeled(with: "line")
assert Ok(policy) = p.parse_entire(string, with: line_parser)
policy
}
fn part1(lines: List(String)) -> Int {
lines
|> list.map(with: parse_line)
|> list.filter(for: is_line_valid1)
|> list.length
}
fn part2(lines: List(String)) -> Int {
lines
|> list.map(with: parse_line)
|> list.filter(for: is_line_valid2)
|> list.length
}
pub fn run() -> Nil {
let test = input_util.read_lines("test02")
assert 2 = part1(test)
assert 1 = part2(test)
let input = input_util.read_lines("day02")
io.debug(part1(input))
io.debug(part2(input))
Nil
}
|
