How does a linked list's memory allocation differ from an array's?

A linked list's memory allocation is dynamic and non-contiguous, while an array's is static and contiguous.

In computer science, the way memory is allocated for different data structures can greatly impact their performance and usage. An array is a static data structure, meaning its size is fixed at the time of creation. It requires a contiguous block of memory, which means all of its elements are stored together in one place. This can be problematic if you need to add or remove elements, as you would need to create a new array of a different size and copy the elements over. However, accessing elements in an array is very fast because you can calculate the exact memory address of each element based on its index.

On the other hand, a linked list is a dynamic data structure, meaning its size can change during the execution of a programme. It does not require a contiguous block of memory; instead, its elements (or 'nodes') can be scattered throughout memory. Each node contains a data element and a 'link' to the next node in the list. This makes adding or removing elements relatively easy, as you just need to update the links between nodes. However, accessing elements in a linked list can be slower than in an array, as you have to traverse the list from the start to find the desired element.

In terms of memory allocation, arrays can be more efficient if the number of elements is known in advance and does not change. However, if the number of elements is likely to change, a linked list can be more efficient as it can grow or shrink as needed without requiring a new block of memory. Furthermore, because linked lists do not require contiguous memory, they can make better use of fragmented memory spaces.

In conclusion, the choice between using an array or a linked list depends on the specific requirements of your programme, including how memory is allocated and used. Understanding these differences can help you make more effective design decisions.