Solutions to Coding Challenges with Explanations

Let's collect as many different solutions for coding challenges as we can! Better yet, let's try to explain them easily!

How to Use This Repo

• Links to challenges are in the 'Challenges' column of the 'Challenges' table below.

• The solutions can be found in the Solutions folder. Links are in the 'Solutions' column of the table below.

• Code for various data structures and algorithms can be found in the 'Data Structures' and 'Algorithms' tables.

• The explainers can be found in the Explainers folder, with more information in the EXPLAINERS.md

Hackerrank Challenges

Challenges	Solutions	Explainers
3D Surface Area	Solution	Explainer
Anagram	Solution	Explainer
Angry Professor	Solution	Explainer
Beautiful Triplets	Solution	Explainer
Birthday Cake Candles	Solution	Explainer
Cavity Map	Solution	Explainer
Chocolate Feast	Solution	Explainer
Divisible Sum Pairs	Solution	Explainer
Electronics Shop	Solution	Explainer
Encryption	Solution	Explainer
Equalize The Array	Solution	Explainer
Even Fibonacci Numbers	Solution	Explainer
Fair Rations	Solution	Explainer
Find Digits	Solution	Explainer
Find The Median	Solution	Explainer
FizzBuzz	Solution	Explainer
Game Of Thrones - I	Solution	Explainer
Grading Students	Solution	Explainer
Halloween Sale	Solution	Explainer
Lisa's Workbook	Solution	Explainer
Manasa And Stones	Solution	Explainer
Palindrome Index	Solution	Explainer
Picking Numbers	Solution	Explainer
Sock Merchant	Solution	Explainer
Staircase	Solution	Explainer
The Hurdle Race	Solution	Explainer
The Time In Words	Solution	Explainer

Codewars Challenges

Challenges	Solutions	Explainers
Abbreviate A Two Word Name	Solution	Explainer
Array Plus Array	Solution	Explainer
Beginner Series #1 School Paperwork	Solution	Explainer
Beginner Series #4 Cockroach	Solution	Explainer
Calculating With Functions	Solution	Explainer
Century From Year	Solution	Explainer
Convert Number To Reversed Array Of Digits	Solution	Explainer
Count By X	Solution	Explainer
Count Letters In String	Solution	Explainer
Count The Monkeys!	Solution	Explainer
Don't Drink The Water	Solution	Explainer
Extract The Domain Name From A URL	Solution	Explainer
Fake Binary	Solution	Explainer
Find The First Non-Consecutive Number	Solution	Explainer
First Non-Repeating Character	Solution	Explainer
Get The Mean Of An Array	Solution	Explainer
How Good Are You Really?	Solution	Explainer
Human Readable Duration Format	Solution	Explainer
Interleaving Arrays	Solution	Explainer
Invert Values	Solution	Explainer
Jenny's Secret Message	Solution	Explainer
Keep Hydrated!	Solution	Explainer
Lottery Ticket	Solution	Explainer
Memoized Fibonacci	Solution	Explainer
Multiplying Numbers As Strings	Solution	Explainer
Permutations	Solution	Explainer
RGB To Hex Conversion	Solution	Explainer
(Ready for) Prime Time	Solution	Explainer
Returning Strings	Solution	Explainer
Reversed Sequence	Solution	Explainer
Snail	Solution	Explainer
Sort Arrays - 3	Solution	Explainer
String Incrementer	Solution	Explainer
Sum Arrays	Solution	Explainer
Sum Of Intervals	Solution	Explainer
Sum Without Highest And Lowest Number	Solution	Explainer
The Hashtag Generator	Solution	Explainer
Total Amount Of Points	Solution	Explainer
Valid Parentheses	Solution	Explainer
You Can't Code Under Pressure #1	Solution	Explainer

Data Structures and Algorithms

Data Structures

Data Structure	Code	Explainers
Array	N/A	Explainers
Singly Linked List	Code	Explainers
Doubly Linked List	Code	Explainers

🤝 Contributing

• Contributions are welcome. Fork the project, make changes, then make a pull request.

• If you're going to suggest a new coding challenge to include on the list, then include your solution along with the coding challenge. Make sure your solution is in the appropriate language folder. Include a link to the coding challenge in the top-level README before making your pull request, and make sure it is passing all test cases.

• If you're going to suggest a new solution to a coding challenge that already has an existing solution in the repo, make sure it fulfils at least one of the following:

  • Has better time complexity than the existing solution
  • Has the same time complexity but involves writing less code
  • Is well commented to explain what is going on

• Optionally, consider writing a short article or making an explainer video where you explain how the algorithm works and the thinking process that led you to that particular solution. I am currently trying to do write-ups for all of my solutions to make these algorithms more accessible and would love assistance on the same. You can add your explanation to the any of the EXPLAINER-*.md documents.

• To suggest a new challenge to add to the list, add it to the (CHALLENGES.md)[./Challenges/CHALLENGES.md] file with a link to the webpage with the challenge. Ideally, the page should have test cases to verify. In case your challenge does not have test cases, please provide test cases along with your challenge.

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📝 License

This project is MIT licensed.