Hi all, I am trying to learn how to write idiomatic Elixir. I decided to write an implementation of a coding challenge I was given long time ago. I wrote the implementation and tests, but.. I don’t like it The problem I see is that I use too many exit checks . The algo is explained on the github …

Here’s mind attempt to create less checks. defmodule CodingTest do def solution([num | rst], target) do q = :queue.new() find(rst, :queue.in(num, q), num, target) end defp find([], _, _, _), do: nil defp find([num | rst], q, sum, target) when sum == target do if :queue.is_empty…

Hi @nikiiv , Here’s my solution. This is as idiomatic as I could make it be. Naming convention, guards, types, specs, pattern matching, optimization (avoids unnecessary traversing), documentation, doctests, and code formatting. Feel free to study the code and ask questions. Later on tonight when…

Thank you so much! It gives a lot of color to how structure Elixir code. The.problem with this implementation is the complexity. I am after O(n), though adding an element to the end of the list is spoiling my solution also

How adding elements to a list spoils your solution? It may look complex but is the most optimal IMO. You only keep what is needed, and stops as soon as a solution is found.

Because Elixir lists are single linked so adding an element to the end requires is an O(n) operation Niki

My solution is of O(n²) complexity. I cannot see how you can solve this problem linearly (O(n)).

Of course, the proper solution would be a sliding window within the original structure The problem with Elixir is that it lacks an internal O(1) access data structure outside of tuples and to solve this one, one needs O(1) access. There are two ways I’ve found so far to solve it. Either use :queue …

I did a benchmark of the solutions presented here and @100phlecs ’s solution is still the fastest, but your second solution uses the least memory. See: benchmark.exs · GitHub Results: Name ips average deviation median 99th % 100phlecs 2.53 M …