Implement vector

Implementing a dynamic array container in C++

This medium-difficulty coding problem tests whether you understand the internals of C++'s vector — one of the most fundamental data structures in competitive programming and systems software. Quant firms and trading platforms use questions like this to verify that you can manage dynamic memory, handle growth policies, and avoid common pitfalls around object construction.

The core challenge is implementing a resizable array that grows efficiently without unnecessary allocations or object copies. Key design decisions include choosing the right growth factor, managing raw memory allocation and deallocation, and understanding when constructors and destructors should fire. The distinction between capacity (allocated space) and size (number of live elements) is central; your implementation must respect that expanding capacity does not invoke default constructors on unused slots.

• Dynamic memory management with new and delete
• Object lifetime and placement: when to construct vs. merely allocate
• Amortized time complexity of resizable containers
• Copy semantics and move operations during reallocation
• Bounds checking and error handling