Structures and Memory Alignment

Explain how a compiler inserts padding bytes into structures for data alignment.

Calculate the size of a struct, including padding, given its member types and alignment rules.

Predict how reordering struct members can change the total size and padding.

Use `#pragma pack` or `__attribute__((packed))` to control struct packing and explain the trade-offs (performance vs. memory size).

Perform pointer arithmetic on struct pointers and predict the resulting memory addresses based on the struct's total size.