When you're logged in, you can say
exercism fetch elm to get the next available exercise on the track.
Every time you submit a solution to an exercise, you will get the next in line the next time you fetch.
If you want to try a specific exercise, you can always fetch it directly (commands are listed below).
The exercises are ordered roughly in order of difficulty.
- Hello World The classical introductory exercise. Just say "Hello, World!"
- Bob Bob is a lackadaisical teenager. In conversation, his responses are very limited.
- Leap Given a year, report if it is a leap year.
- Raindrops Convert a number to a string, the contents of which depend on the number's factors.
- Pangram Determine if a sentence is a pangram.
- 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.
- Triangle Determine if a triangle is equilateral, isosceles, or scalene.
- Scrabble Score Given a word, compute the scrabble score for that word.
- Anagram Given a word and a list of possible anagrams, select the correct sublist.
- Space Age Given an age in seconds, calculate how old someone is in terms of a given planet's solar years.
- 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.
- Difference Of Squares Find the difference between the square of the sum and the sum of the squares of the first N natural numbers.
- Word Count Given a phrase, count the occurrences of each word in that phrase.
- Sum Of Multiples Given a number, find the sum of all the multiples of particular numbers up to but not including that number.
- Hamming Calculate the Hamming difference between two DNA strands.
- Rna Transcription Given a DNA strand, return its RNA complement (per RNA transcription).
- Run Length Encoding Implement run-length encoding and decoding.
- Sublist Write a function to determine if a list is a sublist of another list.
- Nucleotide Count Given a DNA string, compute how many times each nucleotide occurs in the string.
- Series Given a string of digits, output all the contiguous substrings of length `n` in that string.
- Phone Number Clean up user-entered phone numbers so that they can be sent SMS messages.
- Grade School Given students' names along with the grade that they are in, create a roster for the school
- Allergies Given a person's allergy score, determine whether or not they're allergic to a given item, and their full list of allergies.
- Robot Simulator Write a robot simulator.
- List Ops Implement basic list operations
- Atbash Cipher Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.
- Say Given a number from 0 to 999,999,999,999, spell out that number in English.
- Largest Series Product Given a string of digits, calculate the largest product for a contiguous substring of digits of length n.
- 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.
- Grains Calculate the number of grains of wheat on a chessboard given that the number on each square doubles.
- Etl We are going to do the `Transform` step of an Extract-Transform-Load.
- Collatz Conjecture Calculate the number of steps to reach 1 using the Collatz conjecture
- All Your Base Convert a number, represented as a sequence of digits in one base, to any other base.
- Pascals Triangle Compute Pascal's triangle up to a given number of rows.
- Isogram Determine if a word or phrase is an isogram.