Chapter 11 Data Structures. Understand arrays and their usefulness. Understand records and the...

Chapter 11

Data Structures

Understand Understand arraysarrays and their usefulness. and their usefulness.

Understand Understand recordsrecords and the difference between an array and and the difference between an array and a record.a record.

Understand the concept of a Understand the concept of a linked listlinked list and the difference and the differencebetween an array and a linked list.between an array and a linked list.

After reading this chapter, the reader should After reading this chapter, the reader should be able to:be able to:

OOBJECTIVESBJECTIVES

Understand Understand when to use an arraywhen to use an array and and when to use a linked-listwhen to use a linked-list..

Data Structures Data structure

uses a collection of related variables that can be accessed individually or as a whole.

Data structure a scheme for organizing related pieces of data. allowing different operations to be performed on the data.

The basic types of data structures include: files lists arrays records trees tables

ARRAYSARRAYSARRAYSARRAYS11.111.1

Array

Arraya fixed-size, sequenced collection of elements of the same data type.

The subscripts indicate the ordinal number of the element counting from the beginning of the array.

Figure 11-1Twenty individual variables

Figure 11-2 Processing individual variables

Figure 11-3 Arrays with subscripts and indexes

Figure 11-4 Processing an array

Figure 11-5 Frequency array Show the number of elements with the same

value found in a series of numbers.

Figure 11-6 Histogram

A pictorial representation of a frequency array.

Figure 11-7- Part I Two-dimensional array

Figure 11-8 Memory layout

Row-major storage

RECORDSRECORDSRECORDSRECORDS11.211.2

Record

Recorda collection of related elements, possibly of different types, having a single name.

Each element in a record is called a field.

Difference Array: all elements – same type Record: elements – same or different types.

Figure 11-9 Records

The elements in a The elements in a recordrecord can be can be of theof the

samesame or or differentdifferent types. types.

But all elementsBut all elementsin the record must be related.in the record must be related.

Note:Note:

LINKEDLINKEDLISTSLISTS

LINKEDLINKEDLISTSLISTS

11.311.3

Linked list

Linked listan ordered collection of data in which each element contains the location of the next element.

Each element contains two parts: data and link. The link contains a pointer (an address) that identifies the

next element in the list.

Singly linked list The link in the last element contains a null pointer,

indicating the end of the list.

Figure 11-10 Linked lists

Figure 11-11 Node

Nodes : the elements in a linked list.

The nodes in a linked list are called self-referential records. Each instance of the record contains a pointer to another

instance of the same structural type.

Figure 11-12 Inserting a node

Figure 11-13Deleting a node

Figure 11-14 Traversing a list