Second homework solution, Erlang course.

pattern_matching.erl

-module(pattern_matching).
-export([exclusiveOr/2,exclusiveOr2/2,exclusiveOr3/2, maxThree/3, howManyEquals/3]).

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

exclusiveOr2(X,Y) ->
  (X=/=Y).

exclusiveOr3(X,Y) when (X and Y) -> false;
exclusiveOr3(X,Y) when not (X or Y) -> false;
exclusiveOr3(_,_) -> true.

maxThree(X,Y,Z) when ((X > Z) or (Y > Z)) -> max(X,Y);
maxThree(_,_,Z) -> Z.


howManyEquals(X,X,X) -> 3;
howManyEquals(X,Y,Z) when (X == Y) or (X == Z) or (Y == Z) -> 2;
howManyEquals(_,_,_) -> 0.