Announcements

1
Announcements Review

• Course on-line survey due Tuesday 10pm on
  eBlackboard
• Exam Wednesday 12/7
• ACES 2.302
• 530--730
• Tournament cancelled
• Discussion section grades
• drop first 5 or
• average out

• Topics to review
• background
• for, while, if/else,
• read from file
• array of objects
• two dimensional arrays
• Color
• sorting
• bubble, quick, merge
• recursion
• GUI

2
Basic Exam Format

• Open book, open notes
• - No computers or cell phones
• - I suggest you print out your programming
• assignment solutions and/or my in
  class examples
• 5 questions
• 4 short answer, similar to previous exam
• object allocation
• I/O and efficient representation computation
• Image manipulation
• Class design

3
Topics you understand

• for loops
• while loops
• I/O
• conditionals
• classes, objects, methods, instance variables
• arrays
• --------------------------------------------------
  ------
• File input
• Image manipulation
• Sorting
• Recursion
• GUI

4
File Input

• use Scanner class
• same methods used with terminal
• nextInt()
• next()
• hasNextInt()

5
Image Manipulation

• int myPixels
• height myPixels.length
• width myPixels0.length
• int -gt Color
• myColor new Color(myPixelsij)
• Color -gt int
• myPixelsij myColor.getRGB()
• Color manipulation
• Color black new Color(0,0,0)
• int red myColor.getRed()
• getGreen(), getBlue()

6
Sorting - BubbleSort

• one element at a time
• moving 765432 27 times

8 7 6 5 4 3 2 1
7 8 6 5 4 3 2 1
7 6 8 5 4 3 2 1
7 6 5 8 4 3 2 1
7 6 5 4 8 3 2 1
7 6 5 4 3 8 2 1
7 6 5 4 3 2 8 1
7 6 5 4 3 2 1 8
7
Sorting - MergeSort

• divide by half and sort each half
• moving (1111) (22) (4) 12 times

8 7 6 5 4 3 2 1
8 7 6 5 4 3 2 1
8 7 6 5 4 3 2 1
7 8 5 6 3 4 1 2
5 6 7 8 1 2 3 4
1 2 3 4 5 6 7 8
8
Sorting - QuickSort

• left lt pivot lt right
• moving 7 (32) 1 13 times

8 7 6 5 4 3 2 1
4 3 2 1 5 8 7 6
2 1 3 4 5 6 7 8
1 2 3 4 5 6 7 8
9
BubbleSort Algorithm

• for (int i0 iltarray.length i)
• for (int j0 jltarray.length-i j)
• if (arrayigtarrayj)
• swap arrayi and arrayj

10
MergeSort Algorithm

• MergeSort(array)
• MergeSort(first half)
• MergeSort(second half)
• Merge first and second

11
QuickSort Algorithm

• QuickSort(array)
• choose pivot
• partition array
• //small to left, big to right
• QuickSort(left)
• QuickSort(right)

12
Recursion

• Repetition with a smaller problem size
• organism marking
• merge sort, quick sort
• tower of hanoi
• How to use
• Call the method in itself, with different
  parameter

13
Remember where PC was

• First-In Last-Out

14
Recursion as Stack

• First-In Last-Out

hanoi(1, src, aux, dst)
hanoi(2, src, dst, aux)
hanoi(3, src, aux, dst)
hanoi(1, aux, dst, src)
hanoi(2, aux, src, dst)
hanoi(3, src, aux, dst)
15
Graphical User Interface

• Components, Containers, Layouts
• Components
• an object having a graphical representation that
  can be displayed on the screen and that can
  interact with the user.
• e.g. Canvas, JButton, JLabel, JRadioButton,
  JTextField, JSlider,

16
Container

• Container
• public class Container extends Component
• A generic Abstract Window Toolkit(AWT) container
  object is a component that can contain other AWT
  components.
• Components added to a container are tracked in a
  list.
• e.g. JFrame, JPanel

17
LayoutManager

• public interface LayoutManager
• Defines the interface for classes that know how
  to lay out Containers.
• e.g. BorderLayout, FlowLayout, GridLayout

18
Big Picture
Container(JFrame)
LayoutManager
Components
Components
Components
19
Thank you!