Mathematics
Algorithms
Logic
Numbers
Data Types
Combinations using big ints
#load "nums.cma";; open Num;;
let rec prod a b=
let cmp=Num.compare_num a b in
if cmp>0 then Num.num_of_int 0 else if cmp==0 then b else
let b1=Num.sub_num b (Num.num_of_int 1) in
Num.mult_num b (prod a b1);;
let num_comb n p=
let nlp=Num.sub_num n p in
let (p,nlp)=if (Num.compare_num p nlp)>0 then (nlp,p)else(p,nlp) in
let one=(Num.num_of_int 1) in
Num.div_num (
prod (Num.add_num nlp one) n
) (prod one p);;
let comb (n:int) (p:int) :string=Num.string_of_num (num_comb (Num.num_of_int n) (Num.num_of_int p));;
comb 76 12 |> print_endline;;(* TODO: replace with your own tests, these are just how-to examples.
* OUnit Spec example:
* See http://ounit.forge.ocamlcore.org/api-ounit-2.0.0 for documentation
*)
module Tests = struct
open OUnit
let suite = [
"Suite Name" >:::
[
"Test Name" >:: (fun _ ->
assert_equal "31022118677225" (comb 76 12)
)
]
]
;;
end