update(travis): update for recent elixir v going forward

Author: raksonibs

.travis.yml

@@ -1,8 +1,5 @@
 language: elixir
 elixir:
-  - 1.6.6
-  - 1.7.2
-  - 1.8.2
   - 1.9.0
 
 otp_release:

CONTRIBUTING.md

@@ -15,7 +15,7 @@ We are very happy that you consider implementing algorithms and data structure f
 - Your work will be distributed under [MIT License](License) once your pull request is merged
 - You submitted work fulfils or mostly fulfils our styles and standards
 
-**New implementation** is welcome! For example, new solutions for a problem, different representations for a graph data structure or algorithm designs with different complexity.
+**New implementations** are welcome! For example, new solutions for a problem, different representations for a graph data structure or algorithm designs with different complexity.
 
 **Improving comments** and **writing proper tests** are also highly welcome.
 
@@ -29,21 +29,14 @@ Your contribution will be tested by our [automated testing on Travis CI](https:/
 
 We want your work to be readable by others; therefore, we encourage you to note the following:
 
-
-
 - Original code submission require module definitions or comments to describe your work.
-
-
-
 - Avoid importing external libraries for basic algorithms. Only use those libraries for complicated algorithms.
 - If you need a third party module that is not in the file __mix.exs__, please add it to that file as part of your submission.
+- Format your work, or it will fail the tests.
 
-#### Other Standard While Submitting Your Work
+#### Other Standards While Submitting Your Work
 
-- File extension for code should be `.exs`. Jupiter notebook files are acceptable in machine learning algorithms.
 - Strictly use snake_case (underscore_separated) in your file_name, as it will be easy to parse in future using scripts.
-- Please avoid creating new directories if at all possible. Try to fit your work into the existing directory structure.
-- If possible, follow the standard *within* the folder you are submitting to.
 - If you have modified/added code work, make sure the code compiles before submitting.
 - If you have modified/added documentation work, ensure your language is concise and contains no grammar errors.
 - Do not update the README.md or DIRECTORY.md file which will be periodically autogenerated by our Travis CI processes.

DIRECTORY.md

@@ -1 +1,60 @@
 
+
+## Arithmetic Analysis
+
+## Backtracking
+
+## Blockchain
+
+## Boolean Algebra
+
+## Ciphers
+
+## Compression
+
+## Conversions
+
+## Data Structures
+  * Linked List
+    * [Singly Linked List](https://github.com/TheAlgorithms/Python/blob/master/data_structures/linked_list/singly_linked_list.py)
+
+## Digital Image Processing
+
+## Divide And Conquer
+
+## Dynamic Programming
+
+## File Transfer
+
+## Fuzzy Logic
+
+## Graphs
+
+## Hashes
+
+## Linear Algebra
+
+## Machine Learning
+
+## Maths
+
+## Matrix
+
+## Networking Flow
+
+## Neural Network
+
+## Other
+
+## Project Euler
+
+## Searches
+
+## Sorts
+
+## Strings
+
+## Traversals
+
+## Web Programming
+  

lib/data_structures/linked_list.ex renamed to lib/data_structures/singly_linked_list.ex

@@ -1,15 +1,15 @@
-defmodule Algorithims.DataStructures.LinkedList do
+defmodule Algorithims.DataStructures.SinglyLinkedList do
   defmodule SingleLink, do: defstruct([:value, :reference])
 
   def add_node([], value) do
-    [form_singly_linked_list(value, nil)]
+    [form_link(value, nil)]
   end
 
   def add_node([head | _tail] = list, value) do
-    [form_singly_linked_list(value, head) | list]
+    [form_link(value, head) | list]
   end
 
-  defp form_singly_linked_list(value, reference) do
+  defp form_link(value, reference) do
     %__MODULE__.SingleLink{value: value, reference: reference}
   end
 end

test/data_structures/linked_list_test.exs

@@ -0,0 +1,45 @@
+defmodule Algorithims.DataStructures.SinglyLinkedListTest do
+  alias Algorithims.DataStructures.SinglyLinkedList
+
+  use ExUnit.Case
+  doctest Algorithims
+
+  describe "add_node/2" do
+    test "it works when the list is empty" do
+      assert SinglyLinkedList.add_node([], 3) == [
+               %SinglyLinkedList.SingleLink{
+                 value: 3,
+                 reference: nil
+               }
+             ]
+    end
+
+    test "it adds to the head" do
+      list =
+        SinglyLinkedList.add_node([], 3)
+        |> SinglyLinkedList.add_node(4)
+        |> SinglyLinkedList.add_node(5)
+
+      assert list == [
+               %Algorithims.DataStructures.SinglyLinkedList.SingleLink{
+                 reference: %Algorithims.DataStructures.SinglyLinkedList.SingleLink{
+                   reference: %Algorithims.DataStructures.SinglyLinkedList.SingleLink{
+                     reference: nil,
+                     value: 3
+                   },
+                   value: 4
+                 },
+                 value: 5
+               },
+               %Algorithims.DataStructures.SinglyLinkedList.SingleLink{
+                 reference: %Algorithims.DataStructures.SinglyLinkedList.SingleLink{
+                   reference: nil,
+                   value: 3
+                 },
+                 value: 4
+               },
+               %Algorithims.DataStructures.SinglyLinkedList.SingleLink{reference: nil, value: 3}
+             ]
+    end
+  end
+end