jason-carter

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

mult(X,Y) ->
    X*Y.

double(X) ->
    mult(2,X).

area(A,B,C) ->

jason-carter

-module(patterns).
-export([is_zero/1, xOr/2, xOr2/2, xOr3/2, xOr4/2, xOr5/2]).
-export([maxThree/3, howManyEqual/3]).

%
% The following functions are the examples provided in step 1.14
%
is_zero(0) ->
    true;
is_zero(_) ->

jason-carter

-module(recursion).
-export([fib/1, pieces/1, cake/2, factorial/1, binomialcoefficient/2]).

% Give a recursive definition of the function fib/1 computing the
% Fibonacci numbers...

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

jason-carter

-module(recursion2).
-export([fib/1, fib/3, fib_tests/0, perfect_tests/0, perfect/1]).

% An efficient implementation of fibonacci

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

fib(0, Prev, _) -> Prev;
fib(Cnt, Prev, Curr) -> fib(Cnt-1, Curr, Prev+Curr).

jason-carter

-module(listfuncs).
-export([productd/1, productt/1, productt/2]).
-export([listmaxd/1, listmaxt/1, listmaxt/2]).

%
% Combining list elements: the product of a list
%

% Direct Recursion
productd([]) -> 1; % The multiplying by 0 gives 0, so need to return 1

jason-carter

-module(listcons).
-export([double/1]).
-export([doubleelems/1]).
-export([even/1,evens/1]).

% Erlang Course activity 2.9

% Transforming List Elements
% Define an Erlang function double/1 to double the elements of a list of numbers.

jason-carter

-module(take).
-export([take/2, take_test/0]).

-spec take(integer(), [T]) -> [T].
take(0, _) -> [];
take(_, []) -> [];
take(Cnt, [X|Xs]) when Cnt > 0 -> [X | take(Cnt-1, Xs)].

take_test() ->
    [] = take(0,"hello"),

jason-carter

-module(dedupe).
-export([exists/2,nubfb/1,nubfb/2,nubbf/1,nubbf/2,nub_test/0]).

% nubfb([2,4,1,3,3,1]) = [2,4,1,3]
% nubbf([2,4,1,3,3,1]) = [2,4,3,1]


exists(_, []) -> false;
exists(Val, [X|_Xs]) when Val == X -> true;
exists(Val, [X|Xs]) when Val =/= X -> exists(Val, Xs).

jason-carter

-module(dedupe2).
-export([exists/2,nubfb/1,nubfb/2,nubbf/1,nubbf/2,nub_test/0]).

% nubfb([2,4,1,3,3,1]) = [2,4,1,3]
% nubbf([2,4,1,3,3,1]) = [2,4,3,1]

exists(Val, []) -> [Val];
exists(Val, [X|_Xs]) when Val == X -> [];
exists(Val, [X|Xs]) when Val =/= X -> exists(Val, Xs).

jason-carter

-module(palindrome).
-export([palindrome/1, clean/1, clean/2, palindrome_test/0]).


% palindrome("Madam I\'m Adam") = true

palindrome([]) -> [];
palindrome(List) ->
    CleanList = clean(List),
    ReversedList = lists:reverse(CleanList),