Folded Array

What this C++ language-knowledge question tests

This is a hard question on C++ semantics and memory layout. It requires you to trace through code involving arrays, pointers, and index arithmetic to predict program output. These questions are common in technical interviews at firms where deep language fluency matters—especially when candidates come from other backgrounds.

Solving it demands careful attention to how arrays decay to pointers, how pointer arithmetic works, and how multidimensional or folded array indexing translates to linear memory. Mistakes often stem from confusion between compile-time array dimensions and runtime pointer operations, or miscounting offsets. The question rewards methodical reasoning: map the declared structure, track the pointer conversions, and compute each access carefully.

• Array-to-pointer decay in C++
• Pointer arithmetic and subscript semantics
• Memory layout of multidimensional arrays
• The relationship between a[i], *(a+i), and linear indexing