% samples.erl
%
-module(samples).
-export([factorial/1,factorial2/1,sum/1,suma/1,split/2,sort/1]).

factorial(0) -> 1;
factorial(N) -> N * factorial(N-1).

factorial2(N)     -> factorial2(N,1).
factorial2(0,ACC) -> ACC;
factorial2(N,ACC) -> factorial2(N-1, ACC*N).
 

sum([]) -> 0;
sum([H|T]) ->  H + sum(T).
 

suma(L) -> suma(L,0).
suma([],Acc)    -> Acc;
suma([H|T],Acc) -> suma(T, Acc+H).
 
 
split(P,L) -> split(P,L,[],[]).
 
split(_,[],A,B) -> [A,B];
split(P,[H|T],A,B) when H =< P -> split(P,T,[H|A],  B);
split(P,[H|T],A,B)             -> split(P,T,   A,[H|B]).
 

sort( []   ) -> [];
sort([H|T])  ->
        [A,B] = split(H,T),
        io:format("Pivot ~p: ~p ~p ~p~n",[H,T,A,B]),
        sort(A) ++ [H] ++ sort(B).