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TypeScript track
Exercises
Exercises on the TypeScript track
Join the TypeScript Track
91 exercises to help you master TypeScript
easy
Hello World
The classical introductory exercise. Just say "Hello, World!"
optional values
strings
text formatting
easy
Two Fer
Create a sentence of the form "One for X, one for me."
strings
optional values
text formatting
easy
Resistor Color Duo
Convert color codes, as used on resistors, to a numeric value.
strings
arrays
easy
Leap
Given a year, report if it is a leap year.
booleans
integers
logic
easy
Resistor Color
Convert a resistor band's color to its numeric representation
arrays
strings
easy
RNA Transcription
Given a DNA strand, return its RNA Complement Transcription.
strings
transforming
easy
Space Age
Given an age in seconds, calculate how old someone is in terms of a given planet's solar years.
classes
floating point numbers
easy
Pangram
Determine if a sentence is a pangram.
algorithms
control flow conditionals
control flow loops
lists
maps
searching
strings
easy
Bob
Bob is a lackadaisical teenager. In conversation, his responses are very limited.
control flow conditionals
pattern recognition
polymorphism
regular expressions
strings
unicode
medium
Matrix
Given a string representing a matrix of numbers, return the rows and columns of that matrix.
arrays
control flow conditionals
control flow loops
data structures
matrices
text formatting
medium
Robot Name
Manage robot factory settings.
control flow conditionals
exception handling
randomness
regular expressions
sets
medium
Grade School
Given students' names along with the grade that they are in, create a roster for the school
arrays
maps
sorting
medium
Clock
Implement a clock that handles times without dates.
integers
logic
strings
medium
Secret Handshake
Given a decimal number, convert it to the appropriate sequence of events for a secret handshake.
algorithms
arrays
bitwise operations
control flow conditionals
control flow loops
games
medium
Binary Search
Implement a binary search algorithm.
algorithms
arrays
control flow conditionals
control flow loops
medium
Linked List
Implement a doubly linked list
algorithms
arrays
control flow conditionals
control flow loops
data structures
lists
optional values
medium
Rational Numbers
Implement rational numbers.
algorithms
floating point numbers
math
medium
Atbash Cipher
Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.
algorithms
arrays
control flow conditionals
control flow loops
text formatting
medium
Simple Cipher
Implement a simple shift cipher like Caesar and a more secure substitution cipher
algorithms
control flow conditionals
control flow loops
randomness
strings
text formatting
transforming
medium
Wordy
Parse and evaluate simple math word problems returning the answer as an integer.
control flow conditionals
control flow loops
exception handling
parsing
pattern recognition
regular expressions
strings
hard
List Ops
Implement basic list operations
data structures
lists
recursion
easy
Word Count
Given a phrase, count the occurrences of each word in that phrase.
control flow loops
lists
regular expressions
strings
unicode
hard
Word Search
Create a program to solve a word search puzzle.
arrays
conditionals
loops
equality
optional values
parsing
text formatting
easy
Difference Of Squares
Find the difference between the square of the sum and the sum of the squares of the first N natural numbers.
algorithms
control flow loops
integers
math
easy
Gigasecond
Given a moment, determine the moment that would be after a gigasecond has passed.
time
easy
Reverse String
Reverse a string
for
loops
strings
easy
Triangle
Determine if a triangle is equilateral, isosceles, or scalene.
control flow conditionals
control flow loops
exception handling
integers
medium
Collatz Conjecture
Calculate the number of steps to reach 1 using the Collatz conjecture
conditionals
exception handling
integers
recursion
math
easy
ETL
We are going to do the `Transform` step of an Extract-Transform-Load.
control flow loops
integers
maps
transforming
easy
Protein Translation
Translate RNA sequences into proteins.
arrays
control flow conditionals
control flow loops
strings
easy
Raindrops
Convert a number to a string, the content of which depends on the number's factors.
control flow conditionals
integers
strings
transforming
easy
Hamming
Calculate the Hamming difference between two DNA strands.
control flow conditionals
control flow loops
equality
strings
medium
Nucleotide Count
Given a DNA string, compute how many times each nucleotide occurs in the string.
arrays
control flow conditionals
control flow loops
strings
text formatting
medium
Scrabble Score
Given a word, compute the Scrabble score for that word.
control flow conditionals
control flow loops
maps
strings
medium
Allergies
Given a person's allergy score, determine whether or not they're allergic to a given item, and their full list of allergies.
arrays
bitwise operations
control flow conditionals
control flow loops
easy
Perfect Numbers
Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for positive integers.
arrays
control flow conditionals
control flow loops
integers
math
medium
Complex Numbers
Implement complex numbers.
arrays
control flow conditionals
control flow loops
math
medium
Luhn
Given a number determine whether or not it is valid per the Luhn formula.
control flow conditionals
control flow loops
integers
strings
medium
Grains
Calculate the number of grains of wheat on a chessboard given that the number on each square doubles.
control flow conditionals
control flow loops
integers
medium
Pythagorean Triplet
There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the product a * b * c.
algorithms
control flow conditionals
control flow loops
integers
math
medium
Sum Of Multiples
Given a number, find the sum of all the multiples of particular numbers up to but not including that number.
control flow conditionals
control flow loops
integers
lists
math
easy
Acronym
Convert a long phrase to its acronym
control flow loops
regular expressions
strings
transforming
easy
Anagram
Given a word and a list of possible anagrams, select the correct sublist.
filtering
strings
easy
Isogram
Determine if a word or phrase is an isogram.
ascii
control flow conditionals
control flow loops
filtering
searching
strings
easy
Roman Numerals
Write a function to convert from normal numbers to Roman Numerals.
control flow conditionals
control flow loops
pattern recognition
transforming
easy
Series
Given a string of digits, output all the contiguous substrings of length `n` in that string.
control flow loops
exception handling
strings
text formatting
medium
Phone Number
Clean up user-entered phone numbers so that they can be sent SMS messages.
parsing
transforming
medium
Two Bucket
Given two buckets of different size, demonstrate how to measure an exact number of liters.
algorithms
arrays
exception handling
games
parsing
conditionals
loops
medium
Variable Length Quantity
Implement variable length quantity encoding and decoding.
algorithms
arrays
bitwise operations
exception handling
lists
loops
transforming
conditionals
loops
medium
Largest Series Product
Given a string of digits, calculate the largest product for a contiguous substring of digits of length n.
control flow conditionals
control flow loops
exception handling
integers
regular expressions
strings
math
medium
Food Chain
Generate the lyrics of the song 'I Know an Old Lady Who Swallowed a Fly'
algorithms
text formatting
medium
House
Output the nursery rhyme 'This is the House that Jack Built'.
arrays
control flow conditionals
control flow loops
recursion
strings
medium
ISBN Verifier
Check if a given string is a valid ISBN-10 number.
control flow conditionals
control flow loops
pattern recognition
regular expressions
strings
medium
Pig Latin
Implement a program that translates from English to Pig Latin
control flow conditionals
control flow loops
games
regular expressions
strings
transforming
medium
Proverb
For want of a horseshoe nail, a kingdom was lost, or so the saying goes. Output the full text of this proverbial rhyme.
arrays
control flow conditionals
control flow loops
optional values
strings
text formatting
medium
Twelve Days
Output the lyrics to 'The Twelve Days of Christmas'
control flow conditionals
control flow loops
pattern recognition
polymorphism
strings
medium
Beer Song
Produce the lyrics to that beloved classic, that field-trip favorite: 99 Bottles of Beer on the Wall.
control flow conditionals
control flow loops
strings
medium
Say
Given a number from 0 to 999,999,999,999, spell out that number in English.
control flow conditionals
control flow loops
exception handling
integers
strings
text formatting
medium
Rectangles
Count the rectangles in an ASCII diagram.
arrays
control flow conditionals
control flow loops
matrices
strings
medium
Saddle Points
Detect saddle points in a matrix.
arrays
control flow conditionals
control flow loops
integers
lists
matrices
sets
medium
Spiral Matrix
Given the size, return a square matrix of numbers in spiral order.
arrays
control flow conditionals
control flow loops
data structures
matrices
medium
Transpose
Take input text and output it transposed.
arrays
control flow conditionals
control flow loops
lists
matrices
strings
text formatting
medium
OCR Numbers
Given a 3 x 4 grid of pipes, underscores, and spaces, determine which number is represented, or whether it is garbled.
control flow conditionals
control flow loops
equality
exception handling
integers
parsing
text formatting
medium
Nth Prime
Given a number n, determine what the nth prime is.
algorithms
control flow conditionals
control flow loops
exception handling
integers
math
medium
Alphametics
Write a function to solve alphametics puzzles.
algorithms
games
medium
Connect
Compute the result for a game of Hex / Polygon
arrays
control flow conditionals
control flow loops
games
maps
parsing
hard
Bowling
Score a bowling game
arrays
control flow conditionals
control flow loops
exception handling
games
parsing
text formatting
medium
Prime Factors
Compute the prime factors of a given natural number.
algorithms
control flow conditionals
control flow loops
integers
math
medium
Diamond
Given a letter, print a diamond starting with 'A' with the supplied letter at the widest point.
arrays
exception handling
games
parsing
text formatting
conditionals
loops
medium
Pascal's Triangle
Compute Pascal's triangle up to a given number of rows.
control flow conditionals
control flow loops
math
medium
Binary Search Tree
Insert and search for numbers in a binary tree.
algorithms
control flow conditionals
control flow loops
recursion
medium
Sublist
Write a function to determine if a list is a sublist of another list.
arrays
control flow conditionals
control flow loops
data structures
lists
medium
Custom Set
Create a custom set type.
arrays
control flow conditionals
control flow loops
data structures
equality
lists
recursion
sets
hard
Circular Buffer
A data structure that uses a single, fixed-size buffer as if it were connected end-to-end.
arrays
control flow conditionals
control flow loops
data structures
exception handling
lists
medium
Sieve
Use the Sieve of Eratosthenes to find all the primes from 2 up to a given number.
control flow conditionals
control flow loops
integers
recursion
math
medium
Palindrome Products
Detect palindrome products in a given range.
algorithms
control flow conditionals
control flow loops
integers
math
easy
Diffie Hellman
Diffie-Hellman key exchange.
algorithms
arrays
control flow conditionals
control flow loops
exception handling
math
hard
Crypto Square
Implement the classic method for composing secret messages called a square code.
algorithms
arrays
control flow conditionals
control flow loops
regular expressions
sorting
text formatting
transforming
medium
Robot Simulator
Write a robot simulator.
control flow conditionals
control flow loops
exception handling
games
parsing
strings
medium
Kindergarten Garden
Given a diagram, determine which plants each child in the kindergarten class is responsible for.
arrays
control flow conditionals
control flow loops
strings
text formatting
easy
Armstrong Numbers
Determine if a number is an Armstrong number
algorithms
integers
math
easy
Run Length Encoding
Implement run-length encoding and decoding.
control flow conditionals
exception handling
parsing
pattern recognition
regular expressions
strings
text formatting
medium
Rotational Cipher
Create an implementation of the rotational cipher, also sometimes called the Caesar cipher.
ascii
iterators
medium
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.
algorithms
arrays
callbacks
control flow conditionals
control flow loops
filtering
lists
medium
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.
algorithms
callbacks
control flow conditionals
lists
medium
All Your Base
Convert a number, represented as a sequence of digits in one base, to any other base.
control flow conditionals
control flow loops
exception handling
integers
parsing
math
medium
Matching Brackets
Make sure the brackets and braces all match.
parsing
stacks
strings
medium
Flatten Array
Take a nested list and return a single list with all values except nil/null
arrays
lists
loops
recursion
medium
Minesweeper
Add the numbers to a minesweeper board
algorithms
arrays
games
hard
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.
control flow conditionals
control flow loops
equality
exception handling
optional values
parsing
text formatting
hard
React
Implement a basic reactive system.
algorithms
closures
reactive programming