Joakineee

-module(second).

-export([hypotenuse/2,perimeter/2,area/2]).


hypotenuse(X,Y) ->

	math:sqrt(first:square(X) + first:square(Y)).

perimeter(X,Y) ->

Joakineee

-module(first).

-export([double/1,mult/2,area/3,square/1,treble/1]).


mult(X,Y) ->

    X*Y.

double(X) ->

Joakineee

-module(pattern_matching).

-export([xOr_1/2,xOr_2/2,xOr_3/2,xOr_4/2,test_xOr_1/0,test_xOr_2/0,test_xOr_3/0,test_xOr_4/0,test_maxThree/0,test_howManyEqual/0]).


xOr_1(X,Y) -> 
	X =/= Y.

xOr_2(X,Y) -> 
       (X and not Y) or (not X and Y).	

Joakineee

-module(recursive).

-export([fib/1,pieces/1]).

fib(0) -> 0;
fib(1) -> 1;
fib(X) when X > 1-> fib(X-2) + fib(X-1).

%Steep by steep evaluation:
%fib(4) -> fib(2) + fib(3)

Joakineee

-module(trecursive).

-export([fib/1,perfect/1,test/0]).

fib(X) -> fib(X,0,1).


fib(0,Acc1,_) -> 
	Acc1;
fib(X,Acc1,Acc2) when X >= 1 -> 

Joakineee

-module(pat).

-export([perimeter/1,area/1,enclosure/1,bits/1,bits_rec/1,tests/0]).

%Shapes exercises
%I considered not necessary to validate the shapes as john don't use it during his examples,
% forexp in circle R > 0 and in triangle A + B > C,etc..

perimeter({circle,_,Radius}) ->
	2 * math:pi() * Radius;

Joakineee

-module(w2lists).

-export([prod/1,mymax/1,test/0]).

%Moddified according Elbrujohalcon:
%Removed the "list is emty" function clause as we will let it crash.
%prod([]) -> 
%	"list is empty";
prod([H|T]) -> 
        prod(T,H).

Joakineee

-module(constructing_lists).

-export([double/1,evens/1,test/0,median/1,modes/1]).

%double function start here.
double(L) -> double(L,[]).

double([],Acc) -> 
	reverse(Acc,[]);
double([H|T],Acc) -> 

Joakineee

-module(take).

-export([take/2]).

-spec take(integer(),list()) -> list().
take(X,L) -> take(X,L,[]).

-spec take(integer(),list(),list()) -> list().
take(_,[],Acc) -> lists:reverse(Acc);
take(0,_,Acc) -> lists:reverse(Acc);

Joakineee

-module(nub).

-export([test/0,nub/1]).


-spec nub(list()) -> list().
nub(L) -> nub(L,[]).

%Adds non repeated elements to the list.
-spec nub(list(),list()) -> list().