Recursive solution for Longest Substring Without Repeating Characters written in Elixir

Multi tool use
Multi tool use

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP





.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty margin-bottom:0;







up vote
4
down vote

favorite












Here's my recursive implementation of a sliding window algorithm to find the longest substring of a given string without repeating characters. Is there a more idiomatic-Elixir way to write this?



defmodule MyString do
 def length_of_longest_substring(string), do: string |> length_of_longest_substring(0, 0, 0, %)

 defp length_of_longest_substring(string, start_index, end_index, longest, indexes) do
 if end_index >= String.length(string) do
 longest
 else
 currrent_char = String.at(string, end_index)
 previous_occurrence = Map.get(indexes, currrent_char, -1)
 updated_indexes = Map.put(indexes, currrent_char, end_index)

 cond do
 previous_occurrence >= start_index ->
 string |> length_of_longest_substring(previous_occurrence + 1, end_index, longest, updated_indexes)

 true ->
 longest = max(longest, end_index - start_index + 1)

 string |> length_of_longest_substring(start_index, end_index + 1, longest, updated_indexes)
 end
 end
 end
end



algorithm recursion functional-programming elixir




share|improve this question

























    up vote
    4
    down vote

    favorite












    Here's my recursive implementation of a sliding window algorithm to find the longest substring of a given string without repeating characters. Is there a more idiomatic-Elixir way to write this?



    defmodule MyString do
     def length_of_longest_substring(string), do: string |> length_of_longest_substring(0, 0, 0, %)

     defp length_of_longest_substring(string, start_index, end_index, longest, indexes) do
     if end_index >= String.length(string) do
     longest
     else
     currrent_char = String.at(string, end_index)
     previous_occurrence = Map.get(indexes, currrent_char, -1)
     updated_indexes = Map.put(indexes, currrent_char, end_index)

     cond do
     previous_occurrence >= start_index ->
     string |> length_of_longest_substring(previous_occurrence + 1, end_index, longest, updated_indexes)

     true ->
     longest = max(longest, end_index - start_index + 1)

     string |> length_of_longest_substring(start_index, end_index + 1, longest, updated_indexes)
     end
     end
     end
    end



    algorithm recursion functional-programming elixir




    share|improve this question





















      up vote
      4
      down vote

      favorite









      up vote
      4
      down vote

      favorite











      Here's my recursive implementation of a sliding window algorithm to find the longest substring of a given string without repeating characters. Is there a more idiomatic-Elixir way to write this?



      defmodule MyString do
       def length_of_longest_substring(string), do: string |> length_of_longest_substring(0, 0, 0, %)

       defp length_of_longest_substring(string, start_index, end_index, longest, indexes) do
       if end_index >= String.length(string) do
       longest
       else
       currrent_char = String.at(string, end_index)
       previous_occurrence = Map.get(indexes, currrent_char, -1)
       updated_indexes = Map.put(indexes, currrent_char, end_index)

       cond do
       previous_occurrence >= start_index ->
       string |> length_of_longest_substring(previous_occurrence + 1, end_index, longest, updated_indexes)

       true ->
       longest = max(longest, end_index - start_index + 1)

       string |> length_of_longest_substring(start_index, end_index + 1, longest, updated_indexes)
       end
       end
       end
      end



      algorithm recursion functional-programming elixir




      share|improve this question











      Here's my recursive implementation of a sliding window algorithm to find the longest substring of a given string without repeating characters. Is there a more idiomatic-Elixir way to write this?



      defmodule MyString do
       def length_of_longest_substring(string), do: string |> length_of_longest_substring(0, 0, 0, %)

       defp length_of_longest_substring(string, start_index, end_index, longest, indexes) do
       if end_index >= String.length(string) do
       longest
       else
       currrent_char = String.at(string, end_index)
       previous_occurrence = Map.get(indexes, currrent_char, -1)
       updated_indexes = Map.put(indexes, currrent_char, end_index)

       cond do
       previous_occurrence >= start_index ->
       string |> length_of_longest_substring(previous_occurrence + 1, end_index, longest, updated_indexes)

       true ->
       longest = max(longest, end_index - start_index + 1)

       string |> length_of_longest_substring(start_index, end_index + 1, longest, updated_indexes)
       end
       end
       end
      end




      algorithm recursion functional-programming elixir





      share|improve this question










      share|improve this question




      share|improve this question









      asked Apr 3 at 11:24









      Eli

      212




      212

























          active

          oldest

          votes











          Your Answer




          StackExchange.ifUsing("editor", function ()
          return StackExchange.using("mathjaxEditing", function ()
          StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
          StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
          );
          );
          , "mathjax-editing");

          StackExchange.ifUsing("editor", function ()
          StackExchange.using("externalEditor", function ()
          StackExchange.using("snippets", function ()
          StackExchange.snippets.init();
          );
          );
          , "code-snippets");

          StackExchange.ready(function()
          var channelOptions =
          tags: "".split(" "),
          id: "196"
          ;
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function()
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled)
          StackExchange.using("snippets", function()
          createEditor();
          );

          else
          createEditor();

          );

          function createEditor()
          StackExchange.prepareEditor(
          heartbeatType: 'answer',
          convertImagesToLinks: false,
          noModals: false,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: null,
          bindNavPrevention: true,
          postfix: "",
          onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          );



          );








           

          draft saved


          draft discarded


















          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f191149%2frecursive-solution-for-longest-substring-without-repeating-characters-written-in%23new-answer', 'question_page');

          );

          Post as a guest






















          active

          oldest

          votes













          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes










           

          draft saved


          draft discarded


























           


          draft saved


          draft discarded














          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f191149%2frecursive-solution-for-longest-substring-without-repeating-characters-written-in%23new-answer', 'question_page');

          );

          Post as a guest
































































          Iek,Wa8D,zcW5PWsd9JispXobi HuVZBhOxw,CqFV,7dHoHjWys,KQAJAnPn
          -
          js,mbrduMxk eODiZw 496x

          Popular posts from this blog

          Chat program with C++ and SFML

          Image
          Clash Royale CLAN TAG #URR8PPP .everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty margin-bottom:0; up vote 2 down vote favorite This is my client code: (My server is very similar at the moment but I will upload it below this one just in case somebody wants to run it) #include <SFML/Graphics.hpp> #include <SFML/Network.hpp> #include <thread> int main() sf::RenderWindow main_win(sf::VideoMode(800, 800), "Chatcy!"); main_win.setPosition(sf::Vector2i(sf::VideoMode::getDesktopMode().width/2 -400, sf::VideoMode::getDesktopMode().height/2 -400)); main_win.setVerticalSyncEnabled(true); //chatcy logo sf::Texture chatcy; chatcy.loadFromFile("image_chatcy.png"); sf::Sprite logo; logo.setTexture(chatcy); //200x800 //font sf::Font font; font.loadFromFile("FreeSerif.ttf"); //name sf::String name("Client"); name += ": "; //text input area and background sf::RectangleShape in_backg...
          Read more

          Function to Return a JSON Like Objects Using VBA Collections and Arrays

          Image
          Clash Royale CLAN TAG #URR8PPP .everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty margin-bottom:0; up vote 1 down vote favorite My goal is to create a compact function that can create a JSON Like object from JSON string. I want a function with a small footprint that I or anyone who wants to use it, can simply paste into a module and use. At 61 lines of code, I am happy with its size and portability. Here is an image of JSON Object created from string data using a ScriptControl . Although the Locals Window displays the properties and values correctly, the object itself is extremely difficult to work with. This image shows an object created using getJSONCollection . Because it is made of VBA Collections and Arrays, it is very easy to work with. Option Explicit Private Function getJSONCollection(ByVal Value As Variant, Optional ScriptEngine As Object) As Variant Const DELIMITER As String = "||" Dim col As Collection, JSON As Object, KeyNam...
          Read more

          Python - Quiz Game with Tkinter

          Image
          Clash Royale CLAN TAG #URR8PPP .everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty margin-bottom:0; up vote 4 down vote favorite I have made a little Quiz Game in Python. This was my first experience in programming Gui's in Python with Tkinter. In general, I do not have much knowledge about graphic programming and have acquired the necessary knowledge through skimming internet articles and try and error. Accordingly, the code looks like sciolism and semi-professional structuring. That should be improved. I will not be able to avoid a good basic tutorial on graphic programming, I think. However, if you have tips for me how to improve the style I would be grateful to hear them. from tkinter import Tk, Frame, Label, Button from time import sleep class Question: def __init__(self, question, answers, correctLetter): self.question = question self.answers = answers self.correctLetter = correctLetter def check(self, letter, view): global right if...
          Read more