10.8.ml

(* 型定義 *)
type date_t = {
    month : int;
    day : int;
  }
		
type person_t = {
    name : string;
    height : float;
    weight : float;
    birthday : date_t;
    blood : string;
  }

(* テスト用データ *)
let test_data1 = [
    {
      name = "ishimaru";
      height = 1.73;
      weight = 73.2;
      birthday = { month = 10; day = 8; };
      blood="A";
    };
    {
      name = "tachikawa";
      height = 1.60;
      weight = 59.2;
      birthday = { month = 12; day = 15; };
      blood = "B";
    };
    {
      name = "kanehara";
      height = 1.60;
      weight = 59.2;
      birthday = { month = 12; day = 15; };
      blood = "B";
    };
    {
      name = "kata";
      height = 1.60;
      weight = 59.2;
      birthday = { month = 12; day = 15; };
      blood = "O";
    };
    {
      name = "hidaka";
      height = 1.60;
      weight = 59.2;
      birthday = { month = 12; day = 15; };
      blood = "C";
    };
    {
      name = "shikiuchi";
      height = 1.60;
      weight = 59.2;
      birthday = { month = 12; day = 15; };
      blood = "AB";
    }
  ]

let rec ketsueki_shukei lst = match lst with
    [] -> (0, 0, 0, 0, 0)
  | { name = n; height = h; weight = w; birthday = b; blood = bl } :: rest ->
     let (a, b, o, ab, other) = ketsueki_shukei rest in
     if bl = "A" then (a + 1, b, o, ab, other)
     else if bl = "B" then (a, b + 1, o, ab, other)
     else if bl = "O" then (a, b, o + 1, ab, other)
     else if bl = "AB" then (a, b, o, ab + 1, other)
     else (a, b, o, ab, other + 1)

let t0 = ketsueki_shukei [] = (0, 0, 0, 0, 0)
let t1 = ketsueki_shukei test_data1 = (1, 2, 1, 1, 1)


(* 目的:person_t型を受け取って4つの血液型のうち最も人数の多かった血液型を返す *)
(* saita_ketsueki : person_t list -> string *)
let saita_ketsueki lst =
  let (a, b, o, ab, other) = ketsueki_shukei lst in
  if a >= b && a >= o && a >= ab && a >= other then "A"
  else if b >= o && b >= ab && b >= other then "B"
  else if o >= ab && o >= other then "O"
  else if ab >= other then "AB"
  else "Other"

(* テスト *)
let test1 = saita_ketsueki [] = "A"
let test2 = saita_ketsueki test_data1 = "B"