🧩 LeetCode C++ Solutions — Cross-Platform, VS Code Friendly

🎥 Video explanations available: Each solution in this repository is accompanied by a detailed walkthrough on my YouTube channel — @TrulyLearnedMe. The videos focus on reasoning, trade-offs, and clean Modern C++ implementation.

A fully reproducible Modern C++ project template for solving and testing LeetCode problems. All problem directories are stored under the top-level code/ folder, each following an identical structure designed for clarity, testing, and IDE integration.

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📁 Repository Structure

code/
 ├── 0001_LC_1_Easy_Two_Sum/
 │    ├── .vscode/
 │    │    ├── c_cpp_properties.json
 │    │    ├── launch.json
 │    │    ├── settings.json
 │    │    └── tasks.json
 │    ├── include/
 │    │    ├── solution.h                 # Primary, tested solution
 │    │    ├── solution_brute_force.h     # Alternative approach
 │    │    └── solution_optimal.h         # Alternative approach
 │    ├── src/
 │    │    └── main.cpp                   # Optional demo entry point
 │    ├── tests/
 │    │    └── tests.cpp                  # GoogleTest unit tests
 │    └── CMakeLists.txt
 ├── 0002_LC_20_Easy_Valid_Parentheses/
 │    └── ...
 └── ...

• Every folder inside code/ is independent and self-contained.
• Alternative solutions follow the naming pattern solution_<description>.h.
• main.cpp is only for manual debugging; automated tests are run via GoogleTest.

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⚙️ Toolchain & Compatibility

(Tested with C++23 — fully compatible with C++20)

Platform	Compiler	C++ Standard	Status
macOS 14 +	Clang 17 +	C++23 (✓ C++20)	✅
Windows 11	MSVC 2022 +	C++23 (✓ C++20)	✅
Ubuntu 24.04 +	GCC 15 +	C++23 (✓ C++20)	✅

All builds use strict warnings (-Wall -Wextra -Wpedantic or /W4) and contain no platform-specific code. The same project compiles cleanly and behaves identically across macOS, Windows, and Linux.

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🧪 Testing with GoogleTest

Each problem folder contains its own test suite (tests/tests.cpp). GoogleTest is automatically fetched by CMake.

Build and run tests:

cmake -S . -B build
cmake --build build
cd build
ctest --output-on-failure

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💻 Recommended IDE Setup (Visual Studio Code)

1. Install the following extensions:

   • C/C++ (Microsoft)
   • CMake Tools
   • CTest Adapter (optional)

2. Open the problem folder (e.g., code/0001_LC_1_Easy_Two_Sum) as a VS Code workspace.

3. Configure with CMake (Ctrl + Shift + P → CMake: Configure).

4. Run or debug either:

   • the dummy app target (for quick manual runs), or
   • the problem_tests target (for unit testing).

All .vscode/*.json files are pre-configured for convenient IntelliSense, build, and debugging.

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🧠 Design Notes

• Each problem defines a small solution_lib (INTERFACE library) so headers can be shared between the runner and tests.

  • This library is header-only — it doesn’t compile code itself.
  • It simply exports include paths, C++ standard settings, and compiler flags to any target that links against it.
  • Both the executable (app) and the test binary (problem_tests) link to this same library, ensuring consistent configuration and zero duplication.

• CMake enables CTest and registers all GoogleTests automatically.

• Every solution header documents algorithmic complexity and design remarks.

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🧰 Extending the Repository

To add a new problem:

1. Duplicate any existing numbered folder inside code/.
2. Update the name and CMakeLists.txt project() line.
3. Replace contents of include/solution.h and adjust tests/tests.cpp.
4. Re-run CMake and tests.

Optionally, a root-level CMakeLists.txt can be created to include all subprojects in the code/ folder automatically.

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📜 License

MIT — free to fork, learn from, and adapt.