Code Challenges
Prove your coding skills, earn points and get your place on our Leaderboard
Build your own Code Challenge and be rewarded!
Build a Code ChallengeMerge Linked Lists
Avg. Reward: 52 (52%) in 20 submissions
You are given two linked lists. Return a single list that alternately has elements from both lists
Leap Year
Avg. Reward: 85 (85%) in 55 submissions
Tell if a given year in the Gregorian calendar is a leap year or not
Efficient Power Modulo n
Avg. Reward: 61 (61%) in 665 submissions
Create an efficient function that computes exponents followed by modulo
FizzBuzz
Avg. Reward: 74 (74%) in 870 submissions
FizzBuzz is presented as the lowest level of comprehension required to illustrate adequacy.
Pangram checker
Avg. Reward: 69 (69%) in 81 submissions
Write a function or method to check a sentence to see if it is a pangram or not and show its use.
Basic decryption
Avg. Reward: 197 (56%) in 24 submissions
In this challenge you'll receive a basic encrypted string with the format: "##" and decrypt it
Convert Hex to Base64 without using built-in language fucntions
Avg. Reward: 67 (67%) in 6 submissions
The string: 496620796f752061726520612070726f6772616d6d696e6720477572752c207468697320776f756c642062652061207069656365206f662063616b652e2e2e Should produce: SWYgeW91IGFyZSBhIHByb2dyYW1taW5nIEd1cnUsIHRoaXMgd291bGQgYmUgYSBwaWVjZSBvZiBjYWtlLi4u
Matching Brackets
Avg. Reward: 162 (54%) in 34 submissions
In this challenge you will have to detect if the brackets in your code are correctly matched.
Type of
Avg. Reward: 216 (86%) in 26 submissions
In this challenge you will have to analyze a string of text and gather the type of each word.
Leave No Word Uncounted
Avg. Reward: 77 (77%) in 160 submissions
In this challenge you need to analyse a string and return the number of words present in that string.
Squad Formation Curse
Avg. Reward: 320 (53%) in 16 submissions
In this problem you will need to calculate the number of ways in which is possible to fiil the squad formation.
Greatest Prime Tailored Number
Avg. Reward: 250 (83%) in 42 submissions
In this challenge you will have to perform some operations with numbers.
Text Manipulation
Avg. Reward: 167 (84%) in 82 submissions
In this challenge you will have to perform some text operations like replacing strings, capitalize words and reordering text.
The Crazy Investor
Avg. Reward: 142 (95%) in 88 submissions
A new investor from Silicon Valley arrived at the Lisbon Challenge with a crazy idea. He created a secret code to challenge each one of the 30 startups in the Lisbon Challenge and he will only invest in the first ones that give him the correct secret code.
Music Event Manager
Avg. Reward: 176 (88%) in 57 submissions
In this challenge you are a music event manager and you have some music shows to organize in 2014. You need to go through your list of bands and check how many bands you have available to each show, based on their style and their free time.
Find the #hashtags
Avg. Reward: 224 (90%) in 112 submissions
In this challenge you will receive a string with a user comment in your social network and you will need to retreive the valid #hashtags that the user inserted during the comment.
Vending Machine
Avg. Reward: 387 (77%) in 38 submissions
In this challenge you will need to develop the algorithm for a vending machine your company is creating.
Using The Force, The Brute Force
Avg. Reward: 189 (95%) in 90 submissions
In this challenge you will be a hacker trying to find out a password from a hash you just got from a database.
Rock-Paper-Scissor Tournament
Avg. Reward: 373 (93%) in 87 submissions
In this challenge you will be the judge in a Rock-Paper-Scissor (RPS) tournament. The rules of RPS are simple: Rock (R) beats Scissor (S), Scissor (S) beats Paper (P) and Paper (P) beats Rock (R).
Date Validator
Avg. Reward: 179 (90%) in 105 submissions
In this challenge you will receive a string containing two dates and you need to validate a few things about those dates.
The Password Strength
Avg. Reward: 182 (91%) in 135 submissions
In this challenge you will receive a string containing a password that the user is trying to set and you will have to make sure that password is valid and secure.
Text Analytics
Avg. Reward: 127 (85%) in 131 submissions
In this challenge you will have to analyze a string of text and gather some analytics about the text.
The Overlapping Squares
Avg. Reward: 196 (65%) in 643 submissions
In this challenge you will receive the coordinates of two squares and you need to determine if there is an overlapping region formed by those two squares and the area of that region.
Multi Operation Calculator
Avg. Reward: 233 (93%) in 146 submissions
In this challenge you need to build a calculator that can perform multiple operation like add, subtract, multiply and divide at the same time.
Building a Basic Calculator
Avg. Reward: 95 (95%) in 272 submissions
In this challenge you need to build a basic calculator that can perform actions like add, subtract, multiply and divide.
The Pair of Characters
Avg. Reward: 99 (99%) in 312 submissions
There are N characters in an array A. All the characters occur only once except one that ocurs twice. Your task is to find out that character that occurs twice. All characters will be lowercase.
Email Address Validation
Avg. Reward: 88 (88%) in 393 submissions
In this challenge you will be provided with inputs of strings that may or not be valid email addresses (Example: some_name@email.com). You will need to detect if the input are valid email address.