Im trying to create a public bool remove(E element) method that removes the first node that includes the element and if no such a node is found it returns false otherwise true...How can I do that ? im having trouble linking the removed node's predecessor to its successor to close the gap created by the node's removal...this is my code so far...thank you
public class SinglyLinkedList<E> {
private final SLNode<E> head;
private final SLNode<E> tail;
int length;
// creates an empty list
public SinglyLinkedList() {
head = new SLNode<E>();
tail = new SLNode<E>();
head.setSuccessor(tail);
length = 0;
}
// adds new node on beginning of the list
public void add(E element) {
SLNode<E> node = new SLNode<E>(element, null);
node.setSuccessor(head.getSuccessor());
head.setSuccessor(node);
}
// adds new node on beginning of the list
public void add(SLNode<E> node) {
node.setSuccessor(head.getSuccessor());
head.setSuccessor(node);
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
SLNode<E> cursor = head.getSuccessor();
while (cursor != tail) {
sb.append(cursor.getElement()).append(" ");
cursor = cursor.getSuccessor();
}
sb.append("\n");
return sb.toString();
}
}
slnode class
public class SLNode<E> {
private E element;
private SLNode<E> successor;
public SLNode() {
element = null;
successor = null;
}
public SLNode(E theElement, SLNode<E> theSuccessor) {
element = theElement;
successor = theSuccessor;
}
public E getElement() {
return element;
}
public void setElement(E newElement) {
element = newElement;
}
public SLNode<E> getSuccessor() {
return successor;
}
public void setSuccessor(SLNode<E> newSuccessor) {
successor = newSuccessor;
}
}
The trick is as you iterate, you need to keep a reference to both the previous and the current element. The reference to the previous element is what lets you close the gap:
public boolean remove(E element) {
SLNode<E> previous = head;
SLNode<E> current = head.getSuccessor();
while (current != tail) {
if (current.getElement().equals(element)) {
previous.setSuccessor(current.getSuccessor());
return true;
}
previous = current;
current = current.getSuccessor();
}
return false;
}