Data Structures

• Describe the difference between an array and a linked list

  Linked list is a dynamic data structure whereas arrays are static

  In an array every element can be accessed directly whereas in a linked list you need to traverse through until the desired element is found

  In an array the contents are stored continuously in memory
• Decsribe what is meant by the term 'Linked List'

  A dynamic data structure that has nodes. Each node consists of data and a pointer that gives the location of the next node
• Explain why a hash table is better suited than a linked list

  Linked list takes longer to search as it requires every node to be checked until desired element is found Whereas, hash table enables direct access to the location where the desired element is found
• Advantage of using Binary Search tree over an array

  Binary Tree can be searched quicker than an array
• State the meaning of static

  size is fixed when the structure is created. The size cannot change during processing.
• State one type of data structure that is always static

  Array
• State meaning of dynamic

  Size can change during processing
• Give one disadvantage of using a dynamic data structure

  more difficult to program and the storage required initially is unknown
• Explain two characteristics you would look for in a hashing algorithm


  Quick to calculate as lots of files need to be hashed

  Provides a smaller output than input so it is quicker to compare the hashes than original data

  Low chance of collision to reduce the risk of different files being marked as the same
• Tuple


  static/immutable/unordered collection of items that cannot be replaced

  or can store more than one data type
• What do casting functions do?


  turn one data type into another