Add new Perl 5 exercises

One of the easiest ways to add new exercises to the Perl 5 track is to translate them from other language tracks on Exercism. This page lists all of the problem specifications in the common pool of exercises which have not yet been implemented in Perl 5.

The icon links to the language-independent description of the problem.

The icon links to the canonical test data.

We also link to all the implementations of each exercise in other languages, which you can use for inspiration.

Once you've picked an exercise, follow the instructions in this guide and submit your pull request to the Perl 5 track repository on GitHub.




Collatz Conjecture

Calculate the number of steps to reach 1 using the Collatz conjecture

Nth Prime

Given a number n, determine what the nth prime is.

Perfect Numbers

Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for natural numbers.

Bracket Push

Make sure the brackets and braces all match.

Run Length Encoding

Implement run-length encoding and decoding.

Flatten Array

Take a nested list and return a single list with all values except nil/null


Given a letter, print a diamond starting with 'A' with the supplied letter at the widest point.

Rotational Cipher

Create an implementation of the rotational cipher, also sometimes called the Caesar cipher.


Correctly determine change to be given using the least number of coins

Circular Buffer

A data structure that uses a single, fixed-size buffer as if it were connected end-to-end.

Two Fer

Create a sentence of the form "One for X, one for me."


Take input text and output it transposed.

Bank Account

Simulate a bank account supporting opening/closing, withdraws, and deposits of money. Watch out for concurrent transactions!

Protein Translation

Translate RNA sequences into proteins.


Implement a basic reactive system.


Compute the result for a game of Hex / Polygon


Implement an evaluator for a very simple subset of Forth

Spiral Matrix

Given the size, return a square matrix of numbers in spiral order.


Tally the results of a small football competition.


Write a function to solve alphametics puzzles.

Complex Numbers

Implement complex numbers.


Make a chain of dominoes.


Pick the best hand(s) from a list of poker hands.

Book Store

To try and encourage more sales of different books from a popular 5 book series, a bookshop has decided to offer discounts of multiple-book purchases.

Isbn Verifier

Check if a given string is a valid ISBN-10 number.

Parallel Letter Frequency

Count the frequency of letters in texts using parallel computation.


Creating a zipper for a binary tree.

Rail Fence Cipher

Implement encoding and decoding for the rail fence cipher.


Count the rectangles in an ASCII diagram.

Two Bucket

Given two buckets of different size, demonstrate how to measure an exact number of liters.

Variable Length Quantity

Implement variable length quantity encoding and decoding.

Diffie Hellman

Diffie-Hellman key exchange.


Reparent a graph on a selected node

Word Search

Create a program to solve a word search puzzle.


Refactor a Markdown parser

Zebra Puzzle

Solve the zebra puzzle.

Error Handling

Implement various kinds of error handling and resource management


Search a file for lines matching a regular expression pattern. Return the line number and contents of each matching line.

Scale Generator

Generate musical scales, given a starting note and a set of intervals.

Dot Dsl

Write a Domain Specific Language similar to the Graphviz dot language

Go Counting

Count the scored points on a Go board.

Reverse String

Reverse a string

Sgf Parsing

Parsing a Smart Game Format string.

Tree Building

Refactor a tree building algorithm.


Implement the logic of the hangman game using functional reactive programming.


Refactor a ledger printer.

Lens Person

Use lenses to update nested records (specific to languages with immutable data).


Report network IO statistics