tree data structure: design and implementation in

8/14/2019 Tree Data Structure: Design and Implementation In

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TreeTree Data Structure: DesignTree Data Structure: Design

and Implementation in Javaand Implementation in Java

resented byAhmad AbdulRehmanKhayam Shah

resented toresented toir Naeem Aslamir Naeem Aslam


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w hy Trees?w Treesw ree Terminologyw &ifference between Tree BinaryTreesw pplications of Treew uffman Coding Treew ne Recursive Tree Algorithm

mplementation

OutlineOutline


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Storing Many ObjectsStoring Many Objects

wWe have examined 2 major waysto store data in the mainmemory of the computer

arrays

use subscripts to immediatelyaccess elements

fast access, but in the old

days would consume morememory that you would likeit to (not true anymore)

linked structures

each node refers to the nextin the collection. To get to


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Another Linked StructureAnother Linked Structure

wWe now turn our attention to

another major way of storing

data: the Tree

One implementation of a tree has

nodes with a left and right

link field (binary tree)

w 1

32

root

edges

nodes


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First Some DefinitionsFirst Some Definitions

wA tree has a set of nodes and

directed edges that connect

them

a directed edge connects a

parent to its children

wTree properties

one node is distinguished as the

root

every node (except the root) is

connected by an edge fromexactly one other node


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General TreesGeneral Trees

wTrees store data in a

hierarchical manner

w

Root node is A A's children are B, C, and D E, F, and D are leaves Length of path from A to E is 2

A

DB C

FE

Trees have layers of nodes,where some are higher,

others are lower.


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Some tree terminologySome tree terminology

Node An element in the tree referencesdata and other nodes

Root The node at the top It is upsidedown!

Parent The node directly above

another node (except root)

ChildThe node(s) below a given node

Size The number of descendants plus

one for the node itself

Leaves Nodes with no children

Levels The root A is at level 0, Eand F are at level 2


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Differences Between A Tree & A Binary TreeDifferences Between A Tree & A Binary Tree

w No node in a binary tree may have adegree more than 2, whereas there isno limit on the degree of a node in a

tree.w A binary tree may be empty; a tree

cannot be empty.

w The subtrees of a binary tree are

ordered; those of a tree are notordered.

Morew Are different when viewed as binary

trees.


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Javas Classes ExampleJavas Classes Example

Root

children of root

grand children of root

great grand

w

Object

Number Throwable OutputStream

Integer Double Exception FileOutputStream

RuntimeException


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Applications of treesApplications of trees

w File Systems Hierarchical files systems include

Unix and DOS

In DOS, each \ represents an edge(In Unix, it's /)

Each directory is a file with a listof all its children

wStore large volumes of data

data can be quickly inserted,removed, and found

w Data structure used in a variety ofsituations

implement data vase management systems com ilers: ex ression tree s mbol tree


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Huffman Coding TreeHuffman Coding Tree

wBinary trees in a famous file

compression algorithm HuffmanCoding Tree

wEach character is stored in a

leaf

wThe code is found by following

the path 0 go left, 1 go right

a is 01

e is 1

'e'

't' 'a'


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Importing Packages Importing Packages

import java.awt.*;\\ importing abstractwindowing toolkit

import java.awt.event.*; \\ importing awt.event

import javax.swing.*; \\ importing javax.swing

import javax.swing.tree.*;\\ importingswing.tree package


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Creating Tree1 classCreating Tree1 class

public class Tree1 extends Jframe \\ extendingclass using Jframe

{public static void main(String args[])

Tree1 frame = new Tree1(" A Tree");\\ creataingtree

frame.setSize(200,200); \\ set frame size

frame.setVisible(true); \\ if false then novisibility


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Creating NodesCreating Nodes

}public Tree1(String title) \\ creating class

setTitle(title); \\ setting title

DefaultMutableTreeNode root=new \\ creating root

DefaultMutableTreeNode ("Engineering");\\ root

name

DefaultMutableTreeNode style=new \\ declare newstyle of root node


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Creating Style to Nodes.Creating Style to Nodes.

DefaultMutableTreeNode ("InformationTechnology");

root.add(style); \\ add sub root or leaf node.

JTree jt=new JTree(root); \\

Container contentPane=getContentPane();\\

container can contain other awt component panel

contentPane.add(new JScrollPane(jt));\\ includingscrollpane class for manage a viewprt


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wEach Tree object has

a reference to an object object so wecan store anything

a link to the left subtree whichcould be an empty tree

a link to the right subtree whichcould be an empty tree

w3 Constructors

two set some data fields to null

(left and right)

wThe data fields are private

Like LinkNode, methods in the

enclosing class can reference


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Memory linked structure diagramMemory linked structure diagram

Computer Science "

00

Engineering

Root


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import java.awt.*;import java.awt.event.*;import javax.swing.*;import javax.swing.tree.*;

public class Tree1 extends JFrame{public static void main(String args[]){Tree1 frame = new Tree1(" A Tree");frame.setSize(200,200);frame.setVisible(true);}public Tree1(String title){setTitle(title);DefaultMutableTreeNode root=new

DefaultMutableTreeNode ("Engineering");DefaultMutableTreeNode style=new

DefaultMutableTreeNode ("InformationTechnology");

root.add(style);


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style=newDefaultMutableTreeNode("Electronics");

root.add(style);style=new DefaultMutableTreeNode

("Computer Science");root.add(style);style=new DefaultMutableTreeNode

("Mechanical");root.add(style);style=new DefaultMutableTreeNode

("Electrical");root.add(style);style=new DefaultMutableTreeNode

("Sound");root.add(style);

JTree jt=new JTree(root);Container contentPane=getContentPane();contentPane.add(new JScrollPane(jt));}}


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ny Questions ?ny Questions ?


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hank youhank you

tree data structure: design and implementation in

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