Compare arrays and linked lists in terms of memory layout and typical operations.

Compare arrays and linked lists in terms of memory layout and typical operations.

• A. Arrays have contiguous memory and fast random access.
• B. Linked lists use arrays of pointers.
• C. Arrays are dynamic in size by default.
• D. Arrays have contiguous memory and fast random access; linked lists store elements in nodes with pointers, enabling cheap insertions/deletions but no constant-time random access.

Answer: (D)

Memory layout dictates how we access and update data for these structures. Arrays allocate a single, contiguous block of memory, so every element sits next to the others. This layout lets you compute any element’s addressFrom its index in constant time, giving fast random access. But because the elements are packed together, inserting or removing in the middle usually means shifting a bunch of elements, which can be costly. Linked lists store each value in its own node and connect nodes with pointers. The elements aren’t stored contiguously, so you must follow pointers to reach positions, which means random access isn’t constant-time. However, if you already have a reference to the position where you want to insert or delete, you can adjust a few pointers and perform the operation cheaply, without moving many other elements. Additional memory overhead comes from storing the pointers in each node. So the statement that arrays have contiguous memory and fast random access, while linked lists use nodes with pointers to enable cheap insertions and deletions but lack constant-time random access, captures the typical trade-offs accurately.

Memory layout dictates how we access and update data for these structures. Arrays allocate a single, contiguous block of memory, so every element sits next to the others. This layout lets you compute any element’s addressFrom its index in constant time, giving fast random access. But because the elements are packed together, inserting or removing in the middle usually means shifting a bunch of elements, which can be costly.

Linked lists store each value in its own node and connect nodes with pointers. The elements aren’t stored contiguously, so you must follow pointers to reach positions, which means random access isn’t constant-time. However, if you already have a reference to the position where you want to insert or delete, you can adjust a few pointers and perform the operation cheaply, without moving many other elements. Additional memory overhead comes from storing the pointers in each node.

So the statement that arrays have contiguous memory and fast random access, while linked lists use nodes with pointers to enable cheap insertions and deletions but lack constant-time random access, captures the typical trade-offs accurately.