Data Structures

1
Data Structures

• Goal organize data
• Criteria facilitate efficient
• storage of data
• retrieval of data
• manipulation of data
• Process
• select and design appropriate data types

2
Examples
3
Tradeoff
4
abstract data type (ADT)
5
implementation of an ADT
6
(No Transcript)
7
Simple Data Types (2.2)
8
Boolean data
9
Character Data
10
Integer Data
11
Sign-magnitude representation
12
Two's complement representation
13
(No Transcript)
14
Biased representation
15
Problems with Integer Representation

• Limited Capacity -- a finite number of bits
• Overflow
• - addition or multiplication can exceed largest
  value permitted by storage scheme
• Underflow
• - subtraction or multiplication can exceed
  smallest value permitted by storage scheme
• Not a perfect representation of (mathematical)
  integers
• can only store a finite (sub)range of them

16
Real Data
17
Problems with Real Representation
18
C-Style One-Dimensional Arrays (2.3)
19
Declaring arrays in C
20
Subscript operator
21
(No Transcript)
22
Array Initialization
23
(No Transcript)
24
(No Transcript)
25
Initializations with no array size specified
26
Addresses
27
(No Transcript)
28
C-Style Multidimensional Arrays
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
Problems with C-Style Arrays

• Capacity cannot change.
• No predefined operations on non-char arrays.
• Must perform bounds checking, size
  restrictions, ...
• C-style arrays aren't self-contained.
• Must pass size (and/or capacity) to
  array-processing functions.
• Solution (OOP)
• Encapsulate array, capacity, size, and operations
  in a class. vector

36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
A commercial for OOP Two programming paradigms

• Object-oriented ( C, Java, and Smalltalk)
• Focuses on the nouns of a problem's specification
• Programmers
• Determine what objects are needed for a problem
  and how they should work together to solve the
  problem.
• Create types called classes made up ofdata
  members and function members to operate on the
  data. Instances of a type (class) are called
  objects.

• Procedural ( C, FORTRAN, and Pascal )
• Action-oriented concentrates on the verbs of a
  problem's specification
• Programmers
• Identify basic tasks to be performed to solve
  problem
• Implement the actions required to do these tasks
  as subprograms (procedures/functions/subroutines)
• Group these subprograms into programs/modules/libr
  aries, which together make up a complete system
  for solving the problem

43
(No Transcript)
44
(No Transcript)