Submission #123335

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Source Code Expand

let id x = x

let repeat f =
  let rec loop acc = function
    | 0 -> List.rev acc
    | n -> loop (f () :: acc) (n - 1) in
  loop []

let take n list =
  let rec take' n list =
    if n = 0 then []
    else match list with
       | [] -> failwith "take"
       | h::t -> h :: take' (n-1) t
  in take' n list

let rec drop n list =
    if n = 0 then list
    else drop (n-1) (List.tl list)

let main () =
  let (n,k) = Scanf.scanf "%d %d\n" (fun i j -> (i,j)) in
  let rate_list = repeat (fun () -> Scanf.scanf "%d " id) n in
  let rate_list = List.map float_of_int rate_list in
  let sorted = List.fast_sort (fun i j -> int_of_float (i -. j)) rate_list in
  let ans_list = drop (n-k) sorted in
  let score = List.fold_left (fun c x -> (c +. x) /. 2.) 0. ans_list in
  Printf.printf "%f\n" score

let _ = main ()

Submission Info

Judge Result