Question

Homework Edit the following file and save it as Cxxxxxxxx.java where xxxxxxxx is replaced by your 8 digit ID number. Remove any initial package declaration that might be added to your file in case you edit it in eclipse. The goal of the homework is to add an Euler tour traversal (see page 348 of the text) to the implementation of the class BinaryTree that we have considered.   Your class Cxxxxxxxx should extend the class BinaryTree and implement just one new method. This file C00000000.java contains a shell for your new class that includes a title line for the method you must code and a main program (based on the BTreeApp demo from class) to check that your method works as it should. The only modifications that you should make are to add one or more methods to the class BinaryTree to provide the traversal method called eulerTour. You should also modify the main method to print your name and 8 digit id number. ********************************************************************/ import java.util.ArrayList; import java.util.Scanner; import class13.BinaryTree; import class13.BNode; public class C00000000 extends BinaryTree { public C00000000() { super(); } public ArrayList> eulerOrder() { return new ArrayList>(); // replace this with code that performs the Euler Tour Traversal } // Demo program to test your method --- change this to display your // name and id number. Also change C00000000 to reflect your ID number. public static void main(String args[]) { C00000000 g = new C00000000<>(); BNode cursor = null; Scanner s = new Scanner(System.in); while (true) { try { System.out.println(g.treePrint(cursor) + " commands act at the *cursor*: E l r X . > < ^ H S Q:"); String cmd = s.next(); if (cmd.charAt(0) == 'E') { ArrayList> tour = g.eulerOrder(); String answer = ""; for (BNode node: tour) answer += node.getData(); System.out.println(answer); } if (cmd.charAt(0) == 'Q') break; if (cmd.charAt(0) == 'H') { System.out.println(g.height()); continue; } if (cmd.charAt(0) == 'S') { System.out.println(g.size()); continue; } if (cmd.charAt(0) == 'X' && cursor != null) { g.removeNode(cursor); cursor = (BNode) g.root(); } if (cmd.charAt(0) == 'l') { String entry = s.next(); if (g.size() > 0) g.addLeft(cursor, entry); else g.addRoot(entry); } if (cmd.charAt(0) == 'r') { String entry = s.next(); if (g.size() > 0) g.addRight(cursor, entry); else g.addRoot(entry); } if (cmd.charAt(0) == '.') cursor = (BNode) g.root(); if (cmd.charAt(0) == '>') cursor = cursor.getRight(); if (cmd.charAt(0) == '<') cursor = cursor.getLeft(); if (cmd.charAt(0) == '^') cursor = (BNode) cursor.getParent(); } catch (Exception e) { System.out.println(e); } } s.close(); } }

Answer 1

Euler walk is as follows:

1. Visit current node
2. Visit subtree rooted at left child
3. Visit current node (again)
4. Visit subtree rooted at right child
5. Visit current node (again)

based on above theory i am giving implementaion of eulertraversal method.

import java.util.ArrayList;
import java.util.Scanner;

import class13.BinaryTree;
import class13.BNode;

public class C00000000<T> extends BinaryTree<T> {

public C00000000() {
super();
}

public ArrayList<BNode<T>> eulerOrder() {
if(BNode=null)
return ;
else
{
eulerOrder(BNode.left); // traversing left
eulerOrder(BNode); //traversing center node
eulerOrder(BNode.right); //traversing right
return new ArrayList<BNode<T>>();
}
// replace this with code that performs the Euler Tour Traversal

}

// Demo program to test your method --- change this to display your
// name and id number. Also change C00000000 to reflect your ID number.

public static void main(String args[]) {
C00000000<String> g = new C00000000<>();
BNode<String> cursor = null;
Scanner s = new Scanner(System.in);
while (true) {
try {
System.out.println(g.treePrint(cursor)
+ " commands act at the *cursor*: E l r X . > < ^ H S Q:");
String cmd = s.next();
if (cmd.charAt(0) == 'E') {
ArrayList<BNode<String>> tour = g.eulerOrder();
String answer = "";
for (BNode<String> node: tour)
answer += node.getData();
System.out.println(answer);
}
if (cmd.charAt(0) == 'Q')
break;
if (cmd.charAt(0) == 'H') {
System.out.println(g.height());
continue;
}
if (cmd.charAt(0) == 'S') {
System.out.println(g.size());
continue;
}
if (cmd.charAt(0) == 'X' && cursor != null) {
g.removeNode(cursor);
cursor = (BNode<String>) g.root();
}
if (cmd.charAt(0) == 'l') {
String entry = s.next();
if (g.size() > 0)
g.addLeft(cursor, entry);
else
g.addRoot(entry);
}
if (cmd.charAt(0) == 'r') {
String entry = s.next();
if (g.size() > 0)
g.addRight(cursor, entry);
else
g.addRoot(entry);
}
if (cmd.charAt(0) == '.')
cursor = (BNode<String>) g.root();
if (cmd.charAt(0) == '>')
cursor = cursor.getRight();
if (cmd.charAt(0) == '<')
cursor = cursor.getLeft();
if (cmd.charAt(0) == '^')
cursor = (BNode<String>) cursor.getParent();
} catch (Exception e) {
System.out.println(e);
}
}
s.close();
}

}