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-rw-r--r--gleam/aoc2023/src/day14/solve.gleam94
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+import adglent.{First, Second}
+import gleam/dict
+import gleam/int
+import gleam/io
+import gleam/list
+import gleam/order
+import gleam/string
+
+fn parse(input) {
+ input
+ |> string.split("\n")
+ |> list.map(string.to_graphemes)
+ |> list.transpose()
+}
+
+fn roll_boulders(strs: List(String)) {
+ {
+ use chunks <- list.map(list.chunk(strs, fn(c) { c == "O" || c == "." }))
+ list.sort(chunks, order.reverse(string.compare))
+ }
+ |> list.flatten
+}
+
+fn score(matrix) {
+ use acc, col <- list.fold(matrix, 0)
+ acc
+ + {
+ use col_acc, char, n <- list.index_fold(list.reverse(col), 0)
+ case char {
+ "O" -> col_acc + n + 1
+ _ -> col_acc
+ }
+ }
+}
+
+pub fn part1(input: String) {
+ input
+ |> parse
+ |> list.map(roll_boulders)
+ |> score()
+ |> string.inspect
+}
+
+fn rotate(matrix) {
+ matrix
+ |> list.map(list.reverse)
+ |> list.transpose
+}
+
+fn spin(matrix) {
+ use acc, _ <- list.fold(list.range(1, 4), matrix)
+ acc
+ |> list.map(roll_boulders)
+ |> rotate
+}
+
+fn spin_cycle(matrix) {
+ let cache = dict.new()
+ check_if_seen(matrix, cache, 1_000_000_000)
+}
+
+fn check_if_seen(matrix, cache, count) {
+ case dict.get(cache, matrix) {
+ Error(Nil) ->
+ check_if_seen(spin(matrix), dict.insert(cache, matrix, count), count - 1)
+ Ok(n) -> {
+ let assert Ok(extra) = int.modulo(count, n - count)
+ list.fold(list.range(1, extra), matrix, fn(acc, _) { spin(acc) })
+ |> score
+ }
+ }
+}
+
+pub fn part2(input: String) {
+ input
+ |> parse
+ |> spin_cycle
+ |> string.inspect
+}
+
+pub fn main() {
+ let assert Ok(part) = adglent.get_part()
+ let assert Ok(input) = adglent.get_input("14")
+ case part {
+ First ->
+ part1(input)
+ |> adglent.inspect
+ |> io.println
+ Second ->
+ part2(input)
+ |> adglent.inspect
+ |> io.println
+ }
+}