Question

Please write the code in the following methods:

1) reverseListv1() THIS IS THE ONE I NEED HELP BECAUSE I CANT FIGURE OUT A SIMPLER WAY TO DO IT

public class DLList {

public DLLNode front;

public DLLNode back;

public DLList(String name) {

this.front = new DLLNode();

this.front.name = name;

this.front.nextnode = null;

this.front.prevnode = null;

this.back = front;

}

public void addNode(DLLNode newNode) {

newNode.nextnode = this.front;

this.front.prevnode = newNode;

this.front = newNode;

}

// Initially, his next person is nobody. When the list gets reversed, now you need to

// tell Isacc that is next person is Mikey. Then you

// move on to Mikey. Mikey learns that his next person is Julia and in the same

// loop iteration Isaac learns from the buffer that his previous person is now nobody.

// The buffer then stores Isaac as the last person processed. When Julia learns that

// her next person is Tim, in the same loop iteration, Mikey learns that his previous

// person is now Isaac. They continue in this way until the old front of the list is

// reached. This becomes the new end of the list, and the list reversal is finished.

// Now get a simpler version of a method to reverse a linked list.

public void reverseListv1() {

// The add method for this class adds items to the FRONT.

// So, iterating through from the first to the last node and

// adding each node in turn to our new list will end up

// reversing the list.

// 1. Get the name from the first node in the list.

// Use the name string to

// construct a new node in a new list "reversedList".

// 3. create a cursor node and point it to front in the original list.

// 4. create a while loop checking foe nextnode != null.

// 5. Iterate through the original list, using the names in the nodes

// to create new nodes that you add to the reversedList.

// 6. Outside the loop, set this.front to the new list's front.

(According to the above requirement, type the code here)

String firstName = front.name;

//System.out.println(firstName);

DLList reversedList = new DLList(firstName);

//System.out.println(reversedList.toString());

DLLNode frontCursor = new DLLNode();

frontCursor = this.front;

while(frontCursor.nextnode != null) {

frontCursor = frontCursor.nextnode;

String currName = frontCursor.name;

DLLNode currNode = new DLLNode(currName);

reversedList.addNode(currNode);

}

this.front = reversedList.front;

}

public String toString(){

String toReturn = "front-->";

DLLNode currentF = this.front;

while(currentF!= null) {

toReturn = toReturn + currentF.nodeString() + "-->" ;

currentF = currentF.nextnode;

}

toReturn = toReturn + "back";

return toReturn;

}

// COMPLETE THE FOLLOWING METHOD THAT RATHER THAN

// REVERSING THE LIST, JUST PRODUCES A STRING THAT

// ALLOWS THE LIST TO BE PRINTED IN REVERSE ORDER.

public String reverseListString() {

String toReturn = "";

(Type you code here)

}

}

public class DLLNode {

public DLLNode nextnode;

public DLLNode prevnode;

public String name;

public DLLNode() {

this.nextnode = null;

this.prevnode = null;

this.name = null;

}

public DLLNode(String name) {

this.nextnode = null;

this.prevnode = null;

this.name = name;

}

public DLLNode(String name, DLLNode nextnode, DLLNode prevnode) {

this.nextnode = nextnode;

this.prevnode = prevnode;

this.name = name;

}

public String nodeString() {

String result = "";

if (this.nextnode == null && this.prevnode == null) {

result = result + "front<--[- | " + this.name + " | -]-->back";

}

else {

result = result + "[- | " + this.name + " | -]";

}

return result;

}

}

public class DLLDriver {

public static void main(String[] args) {

DLList myList = new DLList("Isaac");

DLLNode friend1 = new DLLNode("Mikey");

DLLNode friend2 = new DLLNode("Julia");

myList.addNode(friend1);

myList.addNode(friend2);

myList.addNode(new DLLNode("Tim"));

myList.addNode(new DLLNode("Jon"));

// Testing reverse method 1

System.out.println(myList.toString());

myList.reverseListv1();

System.out.println(myList.toString());

System.out.println();