CODEWITHSUNDEEP
listsortingerlang
Soutzikevich
Soutzikevich

Reputation: 1031

How to sort a list in ascending or descending order?

Is there a way to sort all the elements of a list in ascending or descending order?

> List1 = [4,3,2,6,1,5].
> sort(List1) == [1,2,3,4,5,6]
> true

Upvotes: 1

Views: 3782

Answers (2)

bxdoan
bxdoan

Reputation: 1369

We have a lot of way to sort, so sometime you can do that for yourself. It's the way I learnt Erlang :)

-spec sort(List) -> SortedList when
  List :: [integer()],
  SortedList :: [integer()].
sort([Pivot | Tail]) ->
{Smaller, Larger} = partition(Pivot, Tail, [], []),
sort(Smaller) ++ [Pivot] ++ sort(Larger);
sort([]) -> [].

partition(Check, [Head | Tail], Smaller, Larger) ->
    case Head =< Check of
        true -> partition(Check, Tail, [Head | Smaller], Larger);
        false -> partition(Check, Tail, Smaller, [Head | Larger])
    end;
partition(_, [], Smaller, Larger) -> {Smaller, Larger}.

Upvotes: 3

Soutzikevich
Soutzikevich

Reputation: 1031

lists:sort([2,3,6,5,1,7,13,4]).

or

lists:sort(ListToSort).

will return a sorted list of integers in an ascending order. Thanks to @Dogbert for pointing out the obvious.

Upvotes: 5

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