1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
import gleam/io
import gleam/list
import gleam/string
import gleam/pair
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_policy() -> p.Parser(Policy) {
p.int()
|> p.then_skip(p.grapheme("-"))
|> p.and_then(p.int())
|> p.then_skip(p.grapheme(" "))
|> p.and_then(p.any_grapheme())
|> p.then_skip(p.grapheme(":"))
|> p.then_skip(p.grapheme(" "))
|> p.map(with: fn(x) {
let #(#(min, max), grapheme) = x
Policy(min, max, grapheme)
})
}
fn parse_line(string: String) -> Line {
let line_parser =
parse_policy()
|> p.and_then(p.all_remaining())
|> p.map(fn(t) { Line(pair.first(t), pair.second(t)) })
assert Ok(#(policy, _)) = p.run(line_parser, on: string)
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
}
|
