Through the Buffer

What this C++ buffer and memory-safety question tests

This is a hard C++ question that asks you to diagnose the runtime behaviour of a code snippet. It probes your understanding of buffer boundaries, pointer arithmetic, and undefined behaviour—skills that matter deeply at firms where memory safety and correctness are non-negotiable.

To answer correctly, you need to trace through the code mentally, track where pointers are pointing, and identify whether any operation violates the C++ memory model or causes the program to behave unpredictably. The question rewards careful reasoning about what the standard guarantees and what it leaves undefined.

• Array indexing and pointer arithmetic
• Buffer overflow and out-of-bounds access
• Stack vs. heap allocation
• Undefined behaviour in C++