Exercises on the Perl 5 Track | Exercism

Hello World

The classical introductory exercise. Just say "Hello, World!"

Two Fer

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

Bob

Bob is a lackadaisical teenager. In conversation, his responses are very limited.

Leap

Given a year, report if it is a leap year.

Grains

Calculate the number of grains of wheat on a chessboard given that the number on each square doubles.

Raindrops

Convert a number to a string, the content of which depends on the number's factors.

Hamming

Calculate the Hamming difference between two DNA strands.

ETL

We are going to do the `Transform` step of an Extract-Transform-Load.

Scrabble Score

Given a word, compute the scrabble score for that word.

Word Count

Given a phrase, count the occurrences of each word in that phrase.

Anagram

Given a word and a list of possible anagrams, select the correct sublist.

Difference Of Squares

Find the difference between the square of the sum and the sum of the squares of the first N natural numbers.

Proverb

For want of a horseshoe nail, a kingdom was lost, or so the saying goes. Output the full text of this proverbial rhyme.

Space Age

Given an age in seconds, calculate how old someone is in terms of a given planet's solar years.

Roman Numerals

Write a function to convert from normal numbers to Roman Numerals.

Clock

Implement a clock that handles times without dates.

Prime Factors

Compute the prime factors of a given natural number.

Triangle

Determine if a triangle is equilateral, isosceles, or scalene.

Beer Song

Produce the lyrics to that beloved classic, that field-trip favorite: 99 Bottles of Beer on the Wall.

Phone Number

Clean up user-entered phone numbers so that they can be sent SMS messages.

Robot Name

Manage robot factory settings.

Atbash Cipher

Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.

Accumulate

Implement the `accumulate` operation, which, given a collection and an operation to perform on each element of the collection, returns a new collection containing the result of applying that operation to each element of the input collection.

Crypto Square

Implement the classic method for composing secret messages called a square code.

Trinary

Convert a trinary number, represented as a string (e.g. '102012'), to its decimal equivalent using first principles.

RNA Transcription

Given a DNA strand, return its RNA Complement Transcription.

Allergies

Given a person's allergy score, determine whether or not they're allergic to a given item, and their full list of allergies.

Simple Cipher

Implement a simple shift cipher like Caesar and a more secure substitution cipher

Series

Given a string of digits, output all the contiguous substrings of length `n` in that string.

Luhn

Given a number determine whether or not it is valid per the Luhn formula.

House

Output the nursery rhyme 'This is the House that Jack Built'.

Gigasecond

Given a moment, determine the moment that would be after a gigasecond has passed.

Strain

Implement the `keep` and `discard` operation on collections. Given a collection and a predicate on the collection's elements, `keep` returns a new collection containing those elements where the predicate is true, while `discard` returns a new collection containing those elements where the predicate is false.

Pig Latin

Implement a program that translates from English to Pig Latin

Linked List

Implement a doubly linked list

List Ops

Implement basic list operations

Wordy

Parse and evaluate simple math word problems returning the answer as an integer.

Largest Series Product

Given a string of digits, calculate the largest product for a contiguous substring of digits of length n.

Hexadecimal

Convert a hexadecimal number, represented as a string (e.g. "10af8c"), to its decimal equivalent using first principles (i.e. no, you may not use built-in or external libraries to accomplish the conversion).

Secret Handshake

Given a decimal number, convert it to the appropriate sequence of events for a secret handshake.

Kindergarten Garden

Given a diagram, determine which plants each child in the kindergarten class is responsible for.

Nucleotide Count

Given a DNA string, compute how many times each nucleotide occurs in the string.

Binary Search

Implement a binary search algorithm.

Matrix

Given a string representing a matrix of numbers, return the rows and columns of that matrix.

Pascal's Triangle

Compute Pascal's triangle up to a given number of rows.

Say

Given a number from 0 to 999,999,999,999, spell out that number in English.

Grade School

Given students' names along with the grade that they are in, create a roster for the school

Meetup

Calculate the date of meetups.

Queen Attack

Given the position of two queens on a chess board, indicate whether or not they are positioned so that they can attack each other.

OCR Numbers

Given a 3 x 4 grid of pipes, underscores, and spaces, determine which number is represented, or whether it is garbled.

Palindrome Products

Detect palindrome products in a given range.

Twelve Days

Output the lyrics to 'The Twelve Days of Christmas'

Binary Search Tree

Insert and search for numbers in a binary tree.

Sum Of Multiples

Given a number, find the sum of all the multiples of particular numbers up to but not including that number.

Sieve

Use the Sieve of Eratosthenes to find all the primes from 2 up to a given number.

Food Chain

Generate the lyrics of the song 'I Know an Old Lady Who Swallowed a Fly'

Pythagorean Triplet

There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the product a * b * c.

Saddle Points

Detect saddle points in a matrix.

Robot Simulator

Write a robot simulator.

Minesweeper

Add the numbers to a minesweeper board

Custom Set

Create a custom set type.

Simple Linked List

Write a simple linked list implementation that uses Elements and a List

Sublist

Write a function to determine if a list is a sublist of another list.

All Your Base

Convert a number, represented as a sequence of digits in one base, to any other base.