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import gleam/dict.{type Dict}
import gleam/io
import gleam/int
import gleam/list
import gleam/regex
import gleam/result
import gleam/string
import simplifile
type Atlas =
Dict(String, Dict(String, Int))
pub fn main() {
let assert Ok(data) = simplifile.read(from: "./src/day5/data.txt")
let assert [table, routes] = string.split(data, "\n\n")
let assert [header, ..rows] = string.split(table, "\n")
let dests =
header
|> string.trim()
|> split_on_many_spaces
let atlas = build_atlas(rows, dests)
routes
|> string.split("\n")
|> list.fold(0, fn(acc, route) { acc + find_total_distance(route, atlas) })
|> io.debug
}
fn split_on_many_spaces(str) {
let assert Ok(re_spaces) = regex.from_string("\\s+")
regex.split(re_spaces, str)
}
fn build_atlas(rows, dests) {
rows
|> list.map(split_on_many_spaces)
|> list.fold(dict.new(), fn(acc, row) {
let assert [from, ..raw_dists] = row
let assert Ok(dists) = list.try_map(raw_dists, int.parse)
let to_dict =
dests
|> list.zip(dists)
|> dict.from_list()
dict.insert(acc, from, to_dict)
})
}
fn dist_between(leg: #(String, String), dict: Atlas) -> Int {
let assert Ok(dist) =
dict
|> dict.get(leg.0)
|> result.try(dict.get(_, leg.1))
dist
}
fn find_total_distance(row: String, atlas: Atlas) {
let assert [_, route] = string.split(row, ": ")
string.split(route, " -> ")
|> list.window_by_2
|> list.fold(0, fn(acc, leg) { acc + dist_between(leg, atlas) })
}
|
