When you're logged in, you can say exercism fetch delphi 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.

Available Exercises

  • 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.
  • Rna Transcription Given a DNA strand, return its RNA complement (per RNA transcription).
  • Raindrops Convert a number to a string, the contents of which depend on the number's factors.
  • Hamming Calculate the Hamming difference between two DNA strands.
  • Bank Account Simulate a bank account supporting opening/closing, withdraws, and deposits of money. Watch out for concurrent transactions!
  • Nucleotide Count Given a DNA string, compute how many times each nucleotide occurs in the string.
  • Etl We are going to do the `Transform` step of an Extract-Transform-Load.
  • Grains Calculate the number of grains of wheat on a chessboard given that the number on each square doubles.
  • Collatz Conjecture Calculate the number of steps to reach 1 using the Collatz conjecture
  • 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.
  • Perfect Numbers Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for natural numbers.
  • Binary Search Implement a binary search algorithm.
  • Clock Implement a clock that handles times without dates.
  • Triangle Determine if a triangle is equilateral, isosceles, or scalene.
  • Allergies Given a person's allergy score, determine whether or not they're allergic to a given item, and their full list of allergies.
  • Saddle Points Detect saddle points in a matrix.
  • Circular Buffer A data structure that uses a single, fixed-size buffer as if it were connected end-to-end.
  • Minesweeper Add the numbers to a minesweeper board
  • Roman Numerals Write a function to convert from normal numbers to Roman Numerals.
  • Bowling Score a bowling game
  • 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.
  • Wordy Parse and evaluate simple math word problems returning the answer as an integer.
  • Poker Pick the best hand(s) from a list of poker hands.