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quiz.ml

(* おおもとのデータ *)
let src = [1;2;3;1;3]

(* 0〜max までのリスト *)
let rec nums_in m lst = 
  if m >= 0 
  then nums_in (m-1) (m::lst)
  else lst
let nums m = nums_in m []
	 
(* lst から m の数を数えて返す *)
let rec count_in m lst c =
  match lst with
    [] -> c
  | car::cdr ->
     if car = m 
     then count_in m cdr (c+1)
     else count_in m cdr c
let count m lst = count_in m lst 0

(* lst から mlst(list) に含まれない数を数えて返す *)
let rec count_not_in mlst lst c =
  match lst with
    [] -> c
  | car::cdr ->
     if count car mlst > 0
     then count_not_in mlst cdr c
     else count_not_in mlst cdr (c+1)
let count_not mlst lst = count_not_in mlst lst 0


(*
  a => 1の数
  b => 2の数
  c => 3の数
  d => 1〜3以外の数
 *)
let q_in5 a b c d result =
  if (count 1 (List.append [a;b;c;d] src) = a) &&
       (count 2 (List.append [a;b;c;d] src) = b) &&
	 (count 3 (List.append [a;b;c;d] src) = c) &&
	   (count_not [1;2;3] (List.append [a;b;c;d] src) = d)
  then (a, b, c, d)::result
  else result
let rec q_in4 a b c dlst result =
  match dlst with
    [] -> result
  | car::cdr -> q_in4 a b c cdr (q_in5 a b c car result)
let rec q_in3 a b clst dlst result =
  match clst with
    [] -> result
  | car::cdr -> q_in3 a b cdr dlst (q_in4 a b car dlst result)
let rec q_in2 a blst clst dlst result =
  match blst with
    [] -> result
  | car::cdr -> q_in2 a cdr clst dlst (q_in3 a car clst dlst result)
let rec q_in1 alst blst clst dlst result =
  match alst with
    [] -> result
  | car::cdr -> q_in1 cdr blst clst dlst (q_in2 car blst clst dlst result)
let quiz1 = q_in1 (nums 9) (nums 9) (nums 9) (nums 9) []