33 lines
1.1 KiB
Java
33 lines
1.1 KiB
Java
package net.datastructures;
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/**
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* A simple node class for a doubly-linked list. Each DNode has a
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* reference to a stored element, a previous node, and a next node.
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*
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* @author Roberto Tamassia
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*/
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//begin#fragment DNode
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public class DNode<E> implements Position<E> {
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private DNode<E> prev, next; // References to the nodes before and after
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private E element; // Element stored in this position
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/** Constructor */
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public DNode(DNode<E> newPrev, DNode<E> newNext, E elem) {
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prev = newPrev;
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next = newNext;
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element = elem;
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}
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// Method from interface Position
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public E element() throws InvalidPositionException {
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if ((prev == null) && (next == null))
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throw new InvalidPositionException("Position is not in a list!");
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return element;
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}
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// Accessor methods
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public DNode<E> getNext() { return next; }
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public DNode<E> getPrev() { return prev; }
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// Update methods
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public void setNext(DNode<E> newNext) { next = newNext; }
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public void setPrev(DNode<E> newPrev) { prev = newPrev; }
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public void setElement(E newElement) { element = newElement; }
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}
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//end#fragment DNode
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