Chapter 4

Question 1

What are balanced parentheses?

Answer 1

They are parentheses for which there is a corresponding closing symbol for every opening symbol

Question 2

What is a data field?

Answer 2

It is the part of an object in which the data is stored, e.g. an instance variable of a node in which the data field wen the ould be self.data = data with data being passed as an attribute in the constructor

Question 3

What is a deque?

Answer 3

It is a linear data structure in which you are able to remove and add from both the front and the rear of a list simultaneously. It is good when you want to narrow down to a value in the middle or want to remove from a list and iterate between both sides, so one iteration on one side, then the next iteration would be on the other.

Question 4

What is FIFO?

Answer 4

First in First out, used by queues.

Question 5

What is fully parenthesised?

Answer 5

A fully parenthesised equation means there are brackets around every part of the equation, e.g. A+B+C+D = ((A+B)+C)+D)

Question 6

What is a head?

Answer 6

A head is the beginning of a list, the only item you are able to access directly from an ordered or unordered LinkedList. It is the first node in a linked list and all subsequent nodes are accessed via linked list traversal

Question 7

What is infix?

Answer 7

It is a way of ordering the operator in an expression, with the operator being in between the two operands. Precedence must be specified when using infix notation.

Question 8

What is LIFO?

Answer 8

Last in First out, used by stacks.

Question 9

What is a linear data structure?

Answer 9

All the elements in a linear data structure are sequential, which each element at most having one predecessor and one successor. They are all ordered contiguously in memory except for linked lists.

Question 10

What is a linked list?

Answer 10

A linear data structure in which all items are stored in random memory address and are linked together via pointers in nodes. The nodes contain the data field and a pointer to the next item in the list.

Question 11

What is a node?

Answer 11

A node is a data type which contains a data field, the data that is to be stored and a pointer to a memory address.

Question 12

What is linked list traversal?

Answer 12

A way of traversing a linked list in which the current element is stored in a temporary variable and the next item is retrieved by updating the temporary variable. The traversal ends when the value of the variable IS None

Question 13

What is a palindrome?

Answer 13

A word that is spelt the same forwards as it is backwards, can be checked for using a deque.

Question 14

What is postfix?

Answer 14

A way of ordering operators in expressions, the operator is after the operands e,g, A B +

Question 15

What is precedence?

Answer 15

It is the order of execution for operators, following BIDMAS

Question 16

What is prefix?

Answer 16

A way of ordering operators in expressions, the operator is after the operands, e.g., + A B. Used in scheme

Question 17

What is a queue?

Answer 17

A linear data structure which follows the FIFO principle. The first element in is the first item in the list and you can only remove items from the front and add items to the back.

Question 18

What is a simulation?

Answer 18

The process of creating a model of a real-world system or process and running experiments on that model to understand behavior or test scenarios.