An exercise for the Future Learn Erlang course.

third.erl

%%%-------------------------------------------------------------------
%%% @author josh
%%% @copyright (C) 2017, <COMPANY>
%%% @doc
%%%
%%% @end
%%% Created : 24. Feb 2017 10:36 PM
%%%-------------------------------------------------------------------
-module(third).
-author("josh").

%% API
-export([xOr1/2, xOr2/2, xOr3/2, xOr4/2, maxThree/3, howManyEqual/3]).

xOr1(X,Y)  ->
  X =/= Y.

xOr2(X,Y) ->
  not (X == Y).

xOr3(X,Y) ->
  X and not Y.

xOr4(false, false) ->
  false;
xOr4(false, true) ->
  true;
xOr4(true, false) ->
  true;
xOr4(true, true) ->
  false.

maxThree(X,Y,Z) ->
  A = max(X,Y),
  max(A,Z).

howManyEqual(X,X,X) ->
  3;
howManyEqual(X,X,_) ->
  2;
howManyEqual(_,X,X) ->
  2;
howManyEqual(X,_,X) ->
  2;
howManyEqual(_,_,_) ->
  0.