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