Data Structures

Question 1

What is an Array?

Answer 1

• Linear Data Structure
• Elements are stored in contiguous memory locations
• Can access elements using index
• Stores homogeneous elements

Question 2

What is the applications of Arrays?

Answer 2

Storing Information in a linear fashion. Suitable for applications that require frequent searching.

Question 3

What is an 1DA?

Answer 3

1 Dimensional Array, can be seen as a row.
- Needs contiguous memory
- Elements in a linear sequence
- Only same type elements (Homogeneous)
- Only one index is used.

Question 4

How to declare an 1DA?

Answer 4

Datatype varname[size];

Question 5

How to initialize an 1DA?

Answer 5

Datatype varname[] = {ele1, ele2, ele3, ele4}

Question 6

What is a 2DA?

Answer 6

2 Dimensional Array, can be seen as a table.

• Store elements in sequence.
• It is an Array containing 1DAs, therefore gaining one more dimention.
• Two indices are used, one for row and one for column.

Question 7

How to declare a 2DA?

Answer 7

Datatype varname[rows][cols];

Question 8

Advantages of arrays?

Answer 8

• Random access elements
• Easy sorting and iteration.
• Replacement of multiple variables.

Question 9

Disadvantages of arrays?

Answer 9

• Fixed size, surplus will be “wasted”
• Difficult to insert and delete
• Need contiguous memory

Question 10

Define a Linked List?

Answer 10

• A linear data structure
• Elements can be stored by memory availability (not contiguous)
• Only same type elements (homogeneous)
• Dynamic size
• Easy insertion and deletion
• 1st element is called Root/Head, if lost, all the Linked list will be lost, as it points to the next elements.

Question 11

What are the applications of a Linked List?

Answer 11

• When Memory is Limited
• When requires frequent insertion and deletion

Question 12

What are the types of Linked List?

Answer 12

• Single Linked List
• Double Linked List
• Circular Linked List

Question 13

What is a Single linked List?

Answer 13

The simple Linked List.

• There will be a Head/root Pointer that will link to the first node.
• Each node contains data and a link to the next one.
• The last node will point to null.

Question 14

What is a Double Linked List?

Answer 14

A linked list in wich each node points to both neighbours (previous and next), so we can move forwards and backwards.

• There will be a head/root pointer to the first node.
• The first node will point to the next (second node), and to the previous address (null).
• All middle nodes have two pointers and data.
• The last node will point to null.

Question 15

What is a Circular Linked List?

Answer 15

A linked list in wich the last node points to the first one.

• There will be a head/root pointer to the first node.
• Each node points forwards
• The last node will point to the first node.