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author | J.J <thechairman@thechairman.info> | 2024-05-30 21:49:58 -0400 |
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committer | J.J <thechairman@thechairman.info> | 2024-05-30 21:49:58 -0400 |
commit | 231c2b688d1e6cf0846d46e883da30e042a9c6cf (patch) | |
tree | 98a6d3a461fe190b38b2cf33a708a1d01703fa70 /aoc2023/src/day9/solve.gleam | |
parent | fe088aa5778dcdbaab4dd8d4a7395a91c444b45c (diff) | |
parent | a2c2b728ec6051323ed937f54816089cd2ae9d20 (diff) | |
download | gleam_aoc-231c2b688d1e6cf0846d46e883da30e042a9c6cf.tar.gz gleam_aoc-231c2b688d1e6cf0846d46e883da30e042a9c6cf.zip |
Merge branch 'main' of https://github.com/hunkyjimpjorps/AdventOfCode
Diffstat (limited to 'aoc2023/src/day9/solve.gleam')
-rw-r--r-- | aoc2023/src/day9/solve.gleam | 70 |
1 files changed, 0 insertions, 70 deletions
diff --git a/aoc2023/src/day9/solve.gleam b/aoc2023/src/day9/solve.gleam deleted file mode 100644 index a2cc7ae..0000000 --- a/aoc2023/src/day9/solve.gleam +++ /dev/null @@ -1,70 +0,0 @@ -import adglent.{First, Second} -import gleam/io -import gleam/list -import gleam/string -import gleam/int - -fn parse(input: String, backwards backwards: Bool) -> List(List(Int)) { - use line <- list.map(string.split(input, "\n")) - use n_str <- list.map(maybe_backwards(string.split(line, " "), backwards)) - let assert Ok(n) = int.parse(n_str) - n -} - -fn maybe_backwards(xs: List(a), backwards: Bool) -> List(a) { - case backwards { - False -> list.reverse(xs) - True -> xs - } -} - -fn is_constant(ns: List(Int)) -> Bool { - case list.unique(ns) { - [_] -> True - _ -> False - } -} - -fn take_derivative(ns: List(Int)) -> List(Int) { - ns - |> list.window_by_2 - |> list.map(fn(tup) { tup.0 - tup.1 }) -} - -fn extrapolate(ns: List(Int)) { - case is_constant(ns), ns { - True, [n, ..] -> n - False, [n, ..] -> n + extrapolate(take_derivative(ns)) - _, _ -> panic as "list empty when it shouldn't be" - } -} - -fn part(input: String, backwards backwards: Bool) { - input - |> parse(backwards: backwards) - |> list.fold(0, fn(acc, ns) { extrapolate(ns) + acc }) - |> string.inspect -} - -pub fn part1(input: String) { - part(input, backwards: False) -} - -pub fn part2(input: String) { - part(input, backwards: True) -} - -pub fn main() { - let assert Ok(part) = adglent.get_part() - let assert Ok(input) = adglent.get_input("9") - case part { - First -> - part1(input) - |> adglent.inspect - |> io.println - Second -> - part2(input) - |> adglent.inspect - |> io.println - } -} |