Parallel vector population

Understanding C++ vector behavior and memory allocation

This is a medium-difficulty C++ language-knowledge question that tests your grasp of how vectors manage memory, resize, and handle object construction and destruction. It requires careful tracing of what happens when a vector grows beyond its current capacity.

Questions like this appear in technical interviews because they separate candidates who have memorized C++ semantics from those who truly understand the runtime behavior of standard containers. The answer depends on understanding the difference between a vector's size and capacity, how reallocation works, and the order in which constructors and destructors execute during that process.

• Vector capacity vs. size
• Object lifecycle during container reallocation
• Move semantics and copy elision in resizing