Homework SoursebuildEmptyDoubleThis method should return an empty doublylin
buildEmptyDouble()-This method should return an empty doubly-linked list (a linked list of length 0)
buildListWith5Strings()-This method should return the first node in the linked list
buildListWith5Doubles()-This method should return the first node in the linked list
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package code;
public class DNode {
private E element;
private DNode previous;
public DNode() {
next = null;
element = null;
previous = null;
} /**
* Creates a node storing the specified element. *
* @param elem Element to which the new node should refer
*/
public DNode(E elem) {
next = null;
previous = null;
element = elem;
}
/**
* Get the next node in the linked list. *
* @return Reference to the node following this one
*/
public DNode getNext() {
return next;
}
/**
* Specify that the given node should be before the current one in the linked
* list. *
* @param node node which should come before the current one
*/
public void setPrevious(DNode node) {
previous = node;
}
/**
* Get the previous node in the linked list. *
*@return Reference to the node before this one */
public DNode getPrevious() {
return previous;
}
/** * Specify that the given node should follow the current one in the linked * list. * * @param node node which should follow the current one */
public void setNext(DNode node) {
next = node;
}
/** * Get the element stored within this node. *
* @return Element referred to by the node */
public E getElement() {
return element;
}
/** * Direct the node to store a new element. * * @param elem New element which this node should store */
public void setElement(E elem) {
element = elem;
}
}
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package code;
public static DNode buildEmptyDouble() {
DNode retVal;
}
/** * This method should instantiate and return a doubly-linked list with 5 elements. In
* order, the elements should be the Strings \"Hi\", \"Mom\", \"I\'m\", \"in\", \"Jail\".
* .You will need to instantiate
* and connect any DNode instances yourself. *
* @return Doubly-linked list that contains the 5 Strings in proper order */
public static DNode buildListWith5Strings() {
DNode retVal;
}
/**
* This method should instantiate and return a doubly-linked list with 5 elements. In
* order, the elements should be the Doubles 4.6, -2.3, 273.15, 3.1415, 42.0.
* You will need to instantiate and connect any DNode instances yourself. *
* @return Doubly-linked list that contains the 5 Doubles in proper order
*/
public static DNode buildListWith5Doubles() {
DNode retVal;
}
}
Solution
Hi, Please find implementation of methods.
public static DNode buildListWith5Strings() {
// creating head node
DNode headNode = new DNode(\"Hi\");
// creating second node
DNode second = new DNode(\"Mom\");
// creating third node
DNode third = new DNode(\"I\'m\");
DNode fourth = new DNode(\"in\"); // creating fourth node
DNode fifth = new DNode(\"Jail\"); // creating fifth node
// setting previous and next of head node
headNode.setPrevious(null);
headNode.setNext(second);
// setting previous and next of second node
second.setPrevious(headNode);
second.setNext(third);
// setting previous and next of third node
third.setPrevious(second);
third.setNext(fourth);
// setting previous and next of fourth node
fourth.setPrevious(third);
fourth.setNext(fifth);
// setting previous and next of fifth node
fifth.setPrevious(fourth);
fifth.setNext(null);
return headNode;
}
public static DNode buildListWith5Doubles() {
4.6, -2.3, 273.15, 3.1415, 42.0.
// creating head node
DNode headNode = new DNode(4.6);
// creating second node
DNode second = new DNode(-2.3);
// creating third node
DNode third = new DNode(273.15);
DNode fourth = new DNode(3.1415); // creating fourth node
DNode fifth = new DNode(42.0); // creating fifth node
// setting previous and next of head node
headNode.setPrevious(null);
headNode.setNext(second);
// setting previous and next of second node
second.setPrevious(headNode);
second.setNext(third);
// setting previous and next of third node
third.setPrevious(second);
third.setNext(fourth);
// setting previous and next of fourth node
fourth.setPrevious(third);
fourth.setNext(fifth);
// setting previous and next of fifth node
fifth.setPrevious(fourth);
fifth.setNext(null);
return headNode;
}
