Add new R exercises

One of the easiest ways to add new exercises to the R 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 R.

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 R track repository on GitHub.

Exercises

About

Examples

Atbash Cipher

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

Roman Numerals

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

Gigasecond

Calculate the moment when someone has lived for 10^9 seconds.

Allergies

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

Etl

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

Grade School

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

Clock

Implement a clock that handles times without dates.

Nth Prime

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

All Your Base

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

Bracket Push

Make sure the brackets and braces all match.

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.

Binary Search

Implement a binary search algorithm.

Crypto Square

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

Series

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

Minesweeper

Add the numbers to a minesweeper board

Wordy

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

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.

Say

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

Pig Latin

Implement a program that translates from English to Pig Latin

Run Length Encoding

Implement run-length encoding and decoding.

Sublist

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

Custom Set

Create a custom set type.

List Ops

Implement basic list operations

Ocr Numbers

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

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.

Binary Search Tree

Insert and search for numbers in a binary tree.

Flatten Array

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

Kindergarten Garden

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

Linked List

Implement a doubly linked list

Palindrome Products

Detect palindrome products in a given range.

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.

Change

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.

Food Chain

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

Matrix

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

Simple Cipher

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

Bank Account

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

Diamond

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

Forth

Implement an evaluator for a very simple subset of Forth

House

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

React

Implement a basic reactive system.

Alphametics

Write a function to solve alphametics puzzles.

Connect

Compute the result for a game of Hex / Polygon

Simple Linked List

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

Transpose

Take input text and output it transposed.

Twelve Days

Output the lyrics to 'The Twelve Days of Christmas'

Dominoes

Make a chain of dominoes.

Parallel Letter Frequency

Count the frequency of letters in texts using parallel computation.

Poker

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

Protein Translation

Translate RNA sequences into proteins.

Variable Length Quantity

Implement variable length quantity encoding and decoding.

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.

Rail Fence Cipher

Implement encoding and decoding for the rail fence cipher.

Zipper

Creating a zipper for a binary tree.

Pov

Reparent a graph on a selected node

Proverb

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

Rectangles

Count the rectangles in an ASCII diagram.

Spiral Matrix

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

Word Search

Create a program to solve a word search puzzle.

Diffie Hellman

Diffie-Hellman key exchange.

Grep

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.

Two Bucket

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

Two Fer

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

Zebra Puzzle

Solve the zebra puzzle.

Error Handling

Implement various kinds of error handling and resource management

Markdown

Refactor a Markdown parser

Sgf Parsing

Parsing a Smart Game Format string.

Complex Numbers

Implement complex numbers.

Dot Dsl

Write a Domain Specific Language similar to the Graphviz dot language

Go Counting

Count the scored points on a Go board.

Hangman

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

Ledger

Refactor a ledger printer.

Lens Person

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

Tree Building

Refactor a tree building algorithm.

Paasio

Report network IO statistics