CodeWars

I upload these as-is from my local testing environment.
Typical directory structure for C++ challenges follows:

nkyu-kata-name
├─ include
│  └─ functionname.hpp (module header)
├─ src
│  ├─ functionname.cpp (module implementation)         ⇐ solution
│  └─ main.cpp (improvised unit tests, debugging)
├─ .gitignore (excludes binaries/objects)
└─ README.md

• 2-Kyu ፨ Multi Line Task++: Hello World
• 3-Kyu ፨ Last Digit of a Huge Number
• 4-Kyu ፨ Strings Mix
• 4-Kyu ፨ Large Factorials
• 4-Kyu ፨ Range Extraction
• 4-Kyu ፨ Square Into Squares
• 4-Kyu ፨ Adding Big Numbers
• 4-Kyu ፨ Sums of Perfect Squares
• 4-Kyu ፨ Roman Numerals Helper
• 4-Kyu ፨ Multiply Numbers as Strings
• 5-Kyu ፨ Simple Assembly Interpreter
• 5-Kyu ፨ Directions Reduction
• 5-Kyu ፨ Rot13 Cipher
• 6-Kyu ፨ Reverse or Rotate?
• 7-Kyu ፨ Get Middle