Exercises on the F# Track | Exercism

Hello World

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

Leap

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

control flow if else statements

Bob

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

control flow if else statements

Sum Of Multiples

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

Two Fer

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

optional values

Space Age

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

discriminated unions

floating point numbers

Raindrops

Convert a number to a string, the contents of which depend on the number's factors.

text formatting

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.

Grade School

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

Collatz Conjecture

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

control flow conditionals

control flow loops

Armstrong Numbers

Determine if a number is an Armstrong number

Beer Song

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

text formatting

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.

Kindergarten Garden

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

Clock

Implement a clock that handles times without dates.

structural equality

Robot Simulator

Write a robot simulator.

Allergies

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

bitwise operations

OCR Numbers

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

pattern recognition

Tree Building

Refactor a tree building algorithm.

Binary Search Tree

Insert and search for numbers in a binary tree.

optional values

Pig Latin

Implement a program that translates from English to Pig Latin

Difference Of Squares

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

Gigasecond

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

Reverse String

Reverse a string

RNA Transcription

Given a DNA strand, return its RNA Complement Transcription.

Grains

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

Hamming

Calculate the Hamming difference between two DNA strands.

Nucleotide Count

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

Pangram

Determine if a sentence is a pangram.

ETL

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

Darts

Write a function that returns the earned points in a single toss of a Darts game

floating point numbers

High Scores

Manage a player's High Score list

Triangle

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

Robot Name

Manage robot factory settings.

Error Handling

Implement various kinds of error handling and resource management

discriminated unions

exception handling

optional values

Scrabble Score

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

Proverb

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

text formatting

Protein Translation

Translate RNA sequences into proteins.

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.

Isogram

Determine if a word or phrase is an isogram.

Sieve

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

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.

discriminated unions

Binary Search

Implement a binary search algorithm.

Secret Handshake

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

bitwise operations

Word Count

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

Twelve Days

Output the lyrics to 'The Twelve Days of Christmas'

text formatting

Meetup

Calculate the date of meetups.

Anagram

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

Series

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

Simple Linked List

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

Acronym

Convert a long phrase to its acronym

Matrix

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

All Your Base

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

Largest Series Product

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

House

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

text formatting

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.

Pascal's Triangle

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

List Ops

Implement basic list operations

Prime Factors

Compute the prime factors of a given natural number.

ISBN Verifier

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

Roman Numerals

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

DOT DSL

Write a Domain Specific Language similar to the Graphviz dot language

domain specific languages

Parallel Letter Frequency

Count the frequency of letters in texts using parallel computation.

Linked List

Implement a doubly linked list

Simple Cipher

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

Rotational Cipher

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

Scale Generator

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

Atbash Cipher

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

Food Chain

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

text formatting

Grep

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

text formatting

Custom Set

Create a custom set type.

Crypto Square

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

Ledger

Refactor a ledger printer.

text formatting

Circular Buffer

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

Luhn

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

Bank Account

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

optional values

Markdown

Refactor a Markdown parser

Run Length Encoding

Implement run-length 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.

Spiral Matrix

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

Yacht

Score a single throw of dice in the game Yacht

discriminated unions

Tournament

Tally the results of a small football competition.

text formatting

Word Search

Create a program to solve a word search puzzle.

optional values

Bowling

Score a bowling game

Transpose

Take input text and output it transposed.

Nth Prime

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

Palindrome Products

Detect palindrome products in a given range.

Complex Numbers

Implement complex numbers.

Rational Numbers

Implement rational numbers.

Rail Fence Cipher

Implement encoding and decoding for the rail fence cipher.

Bracket Push

Make sure the brackets and braces all match.

Sublist

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

Change

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

Minesweeper

Add the numbers to a minesweeper board

Diffie Hellman

Diffie-Hellman key exchange.

Dominoes

Make a chain of dominoes.

Rectangles

Count the rectangles in an ASCII diagram.

Wordy

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

Hangman

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

reactive programming

Zebra Puzzle

Solve the zebra puzzle.

Poker

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

discriminated unions

Diamond

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

text formatting

Two Bucket

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

Connect

Compute the result for a game of Hex / Polygon

Say

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

text formatting

React

Implement a basic reactive system.

reactive programming

Variable Length Quantity

Implement variable length quantity encoding and decoding.

bitwise operations

Go Counting

Count the scored points on a Go board.

optional values

Lens Person

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

SGF Parsing

Parsing a Smart Game Format string.

Alphametics

Write a function to solve alphametics puzzles.

Zipper

Creating a zipper for a binary tree.

Forth

Implement an evaluator for a very simple subset of Forth

POV

Reparent a graph on a selected node

Rest API

Implement a RESTful API for tracking IOUs.