Computer Science II

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Computer Science II

• Introduction Review

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Computer Science II

• Day/Time/Room MW/130-310 pm/WS 116
• Text Data Structures Other Objects Using
  CMichael Main Walter SavitchAddison-Wesley,
  2005

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Computer Science II

• Instructor William J. Joel
• Office WS 110
• Office Hours Posted
• Phone 7-9353
• Email joelw_at_wcsu.edu
• Website http//cs.wcsu.edu/joelw

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Course Objectives

• By the end of this course you should be able to
• Discuss the design and implementation of classes
  in C, specifically for dynamic arrays, lists,
  trees and graphs.
• State and describe basic algorithms for list,
  tree and graph, traversals and sorting.
• Evaluate the performance of a given algorithm
  using Big-O notation.

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Tests

• Five (5), non-cumulative tests, approximately 1
  hour in duration
• No mid-term exam
• Cumulative final exam

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Assignments

• Five (5) programming projects.
• No initial project submission will be accepted
  after its due date.
• Students may may re-submit projects, with
  corrections, no later than 24 hours after initial
  return.
• All re-submissions are due by the next project
  due date.

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Attendence

• You are expected to be present for each class
  session.
• If you are absent, it is your responsibility to
  obtain class notes and handouts (if any) from
  your classmates I will not keep extra copies of
  materials after they are initially distributed
  most materials can be found on the courses
  website.
• 24-hour notice must be given if you cannot make a
  scheduled test, otherwise you will receive a
  grade of 0 for the test.

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Grading

• Tests (lowest dropped) 40
• Assignments 30
• Final exam 20
• Class participation 10
• _______________________
• Total 100

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Tentative Topic Outline
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Tentative Topic Outline
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Tentative Topic Outline
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Review

• Personal Assessment Test
• Test duration 30 minutes

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Pointers

• A pointer is an entity that
• References another entity
• Stores the value of an address (memory location)

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Pointers

• p is a pointer variable which stores the address
  of int variable x
• p is a de-referenced pointer
• x is the address of x

How do we do this?
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Pointers

• First, declare p as a pointer to a given datatype
• myType p, x
• Next, assign the address of a variable to p
• p x

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new Operator

• The operator new is used to allocate memory
  storage dynamically
• myType pp new myType
• p now points to a nameless variable of type
  myType
• All dynamically allocation occurs in that part of
  main memory called the heap

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Problems

• Given
• int p, x
• Determine the values of p and x be after
• x 5p xp 10
• How do pointers and call by reference relate to
  each other?

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Dynamic Arrays

• Space for an array can be dynamically allocated
• Int myArray
• myArray new int5
• This creates an unnamed five element integer array

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Dynamic Arrays

• //
• // This program demonstrates how to create a
  dynamic array
• //
• include ltiostream.hgt
• void main()
• int myArray, cnt, num
• cout ltlt "Size "
• cin gtgt num
• cout ltlt endl
• myArray new intnum
• for(cnt0cntltnumcnt)
• cout ltlt cnt ltlt " "

• First, declare a pointer to the array

• Then, allocate space for the array

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Try this!

• Create a class called vector that can
• be indexed like an array
• grow or shrink as needed
• Questions
• What data members and member functions will you
  require?
• How do you overload the indexing operator?
• How do you shrink/grow the data structure?
• Work in teams, 3 students each