regnault.dev
this repo has no description
1import gleam/int
2import gleam/io
3import gleam/list
4import gleam/result
5import gleam/string
6import simplifile
7
8pub fn start() -> Nil {
9 let assert Ok(content) = simplifile.read("inputs/day5.txt")
10 let data = parse(content)
11
12 let _ = io.debug(part1(data))
13 let _ = io.debug(part2(data))
14
15 Nil
16}
17
18type Range {
19 Range(start: Int, end: Int)
20}
21
22type Input {
23 Input(fresh: List(Range), ids: List(Int))
24}
25
26fn parse(data: String) -> Input {
27 let assert [ranges, identifiers] = string.split(data, "\n\n")
28
29 let fresh =
30 string.split(ranges, "\n")
31 |> list.map(fn(range) {
32 let assert [start, end] =
33 string.split(range, "-")
34 |> list.map(int.parse)
35 |> list.map(result.unwrap(_, 0))
36
37 Range(start, end)
38 })
39
40 let ids =
41 string.split(identifiers, "\n")
42 |> list.map(int.parse)
43 |> list.map(result.unwrap(_, 0))
44
45 Input(fresh, ids)
46}
47
48fn part1(data: Input) {
49 list.count(data.ids, fn(x) {
50 list.any(data.fresh, fn(y) { y.start <= x && x <= y.end })
51 })
52}
53
54fn find_to_merge(lst: List(Range), range: Range) {
55 list.filter(lst, fn(x) {
56 { x.start <= range.start && x.end >= range.start }
57 || { x.start <= range.end && x.end >= range.end }
58 || { x.start <= range.start && x.end >= range.end }
59 || { range.start <= x.start && range.end >= x.end }
60 })
61}
62
63fn part2(data: Input) {
64 list.fold(data.fresh, list.new(), fn(acc, range) {
65 let to_merge = [range, ..find_to_merge(acc, range)]
66 let min =
67 list.fold(to_merge, 9_223_372_036_854_775_807, fn(min, r) {
68 case r.start < min {
69 True -> r.start
70 False -> min
71 }
72 })
73
74 let max =
75 list.fold(to_merge, 0, fn(max, r) {
76 case r.end > max {
77 True -> r.end
78 False -> max
79 }
80 })
81
82 list.filter(acc, fn(x) { !list.contains(to_merge, x) })
83 |> list.prepend(Range(min, max))
84 })
85 |> io.debug
86 |> list.fold(0, fn(acc, r) { acc + r.end - r.start + 1 })
87}