(*The spreadsheet consists of rows of apparently-random numbers.*)
(*To make sure the recovery process is on the right track, they*)
(*need you to calculate the spreadsheet's checksum. For each*)
(*row, determine the difference between the largest value and*)
(*the smallest value; the checksum is the sum of all of these*)
(*differences.*)

(*For example, given the following spreadsheet:*)

(*5 1 9 5*)
(*7 5 3*)
(*2 4 6 8*)

    (*The first row's largest and smallest values are 9 and 1, and their*)
    (*difference is 8.*)
    (*The second row's largest and smallest values are 7 and 3, and their*)
    (*difference is 4.*)
    (*The third row's difference is 6.*)

open Batteries

let get_max_min_diff lst =
    (List.max lst) - (List.min lst)

let parse_line line =
    let
        split = String.split_on_char '\t'
    in
        split line
        |> List.map int_of_string
        |> get_max_min_diff

let parse_input input =
    Enum.map parse_line input
    |> Enum.sum


let () =
    "dec2_input"
    |> File.lines_of
    |> parse_input
    |> print_int