Here are all 72 coding challenges problems with full descriptions and my solutions in the programming languages available on SoloLearn: C, C++, C#, Java, Python, Ruby and Swift.
Please consider solving the problems yourself before looking at the solutions if you want to improve your problem-solving skills
You can also check my SoloLearn profile
| Challenge | C | C++ | C# | Java | Python | Ruby | Swift |
|---|---|---|---|---|---|---|---|
| 2D Map | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Argentina | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Average Word Length | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Balconies | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Ballpark Orders | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Building Blocks | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Camel to Snake | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Candles | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Carrot Cake | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Cheer Creator | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| CMYK to RGB | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Convert US Date to EU Date | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Credit Card Validator | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Day of the Week | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Days Between Dates | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Deja Vu | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Digits of Pi | ❌ | ❌ | ❌ | ✔️ | ✔️ | ❌ | ❌ |
| Divisible | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Duct Tape | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Duty Free | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Easter Eggs | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Even Numbers | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Extra-Terrestrials | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Flowing Words | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Fruit Bowl | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Gotham City | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Guard Flamingos | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Halloween Candy | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Hex Color Code Generator | ✔️ | ✔️ | ❌ | ✔️ | ✔️ | ❌ | ❌ |
| Hofstadter's Q-Sequence | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Hovercraft | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| How Far? | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Initials | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Isogram Detector | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| It's a Sign | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Izzy the Iguana | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Jungle Camping | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Kaleidoscopes | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Land Ho | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Longest Common Substring | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Mathematics | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Military Time | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Missing Numbers | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Multiples | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Name Buddy | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Neverland | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| New Driver's License | ❌ | ❌ | ❌ | ✔️ | ✔️ | ❌ | ❌ |
| No Numerals | ❌ | ❌ | ❌ | ❌ | ✔️ | ✔️ | ❌ |
| Number of Ones | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Paint Costs | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Password Validation | ❌ | ❌ | ❌ | ❌ | ✔️ | ✔️ | ✔️ |
| Pig Latin | ❌ | ❌ | ❌ | ❌ | ✔️ | ✔️ | ❌ |
| Poker Hand | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Popsicles | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Roadrunner | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Safety Deposit Boxes | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Secret Message | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Security | ❌ | ❌ | ❌ | ✔️ | ✔️ | ❌ | ❌ |
| Skee-Ball | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Snap, Crackle and Pop | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Snowballing Numbers | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Splitting Strings | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Super Sale | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Symbols | ❌ | ❌ | ❌ | ❌ | ✔️ | ✔️ | ❌ |
| Tax Free | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ | ✔️ |
| Text Decompressor | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| That's Odd | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| The Spy Life | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Vowel Counter | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| Word Rank | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ |
| YouTube Link Finder | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |
| Zip Code Validator | ❌ | ❌ | ❌ | ❌ | ✔️ | ❌ | ❌ |