1.4 Data Types, Data Structures and Algorithms Extra

Question 1

Why would a type of encryption be described as symmetric

Answer 1

If the same key is used to encrypt and decrypt the data

Question 2

Explain why asymmetric encryption is more suited to transactions over the internet than symmetric encyption

Answer 2

Symmetric requires both parties have a copy of the key this couldnt work as eavesdropper may see it. Asymmetric prevents this as there are two keys and the one used to decrpyt it is kept private

Question 3

When writing boolean expressions what should you do

Answer 3

Refer to the diagrams rather than inputs and outputs as it makes it easier

Question 4

Difference between arrays and linked lists when it comes to dynamic

Answer 4

Linked list are dynamic whereas arrays are static

Question 5

Can arrays have elements accessed directed

Answer 5

An array can have any element
accessed directly (i.e. random access)

Question 6

Can linked lists have elements accessed directly

Answer 6

whereas a linked list needs to be
traversed until the desired element is
found

Question 7

What is meant by the term linked list

Answer 7

A dynamic data structure where each node consists of a data item and a pointer which points to the next node

Question 8

Why hash table is better for storing large amounts than a linked list

Answer 8

Linked lists require every node to be checked so will take longer as it gets bigger whereas hash tables enable direct access to location so will take same time no matter how big it is

Question 9

Advantage of storing words in binary search tree over an array

Answer 9

BS tree can be searched quicker than an array

Question 10

How can lists and tuples be ordered with more than one data type

Answer 10

Ordered not sorted