94 lines
2.5 KiB
Java
94 lines
2.5 KiB
Java
import java.util.AbstractQueue;
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import java.util.Iterator;
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import java.util.NoSuchElementException;
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public class ArrayQueue<E> extends AbstractQueue<E> {
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private static final int INITIAL_CAPACITY = 10; // Taille initiale du tableau
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private E[] elements; // Tableau contenant les éléments
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private int head; // Index de la tête de la file
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private int tail; // Index de la queue de la file
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private int size; // Nombre d'éléments dans la file
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@SuppressWarnings("unchecked")
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public ArrayQueue() {
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elements = (E[]) new Object[INITIAL_CAPACITY];
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head = 0;
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tail = 0;
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size = 0;
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}
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@Override
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public boolean offer(E e) {
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if (e == null) {
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throw new NullPointerException("Les éléments null ne sont pas autorisés.");
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}
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if (size == elements.length) {
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redimensionner();
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}
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elements[tail] = e;
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tail = (tail + 1) % elements.length;
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size++;
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return true;
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}
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@Override
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public E poll() {
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if (size == 0) {
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return null;
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}
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E element = elements[head];
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elements[head] = null; // Libération de la référence pour éviter les fuites mémoire
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head = (head + 1) % elements.length;
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size--;
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return element;
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}
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@Override
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public E peek() {
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return (size == 0) ? null : elements[head];
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}
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@Override
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public int size() {
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return size;
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}
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@Override
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public Iterator<E> iterator() {
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return new Iterator<E>() {
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private int index = head;
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private int remaining = size;
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@Override
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public boolean hasNext() {
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return remaining > 0;
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}
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@Override
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public E next() {
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if (!hasNext()) {
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throw new NoSuchElementException();
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}
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E element = elements[index];
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index = (index + 1) % elements.length;
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remaining--;
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return element;
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}
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};
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}
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// Méthode privée pour redimensionner le tableau lorsqu'il est plein
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@SuppressWarnings("unchecked")
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private void redimensionner() {
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int newCapacity = elements.length * 2;
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E[] newElements = (E[]) new Object[newCapacity];
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for (int i = 0; i < size; i++) {
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newElements[i] = elements[(head + i) % elements.length];
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}
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elements = newElements;
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head = 0;
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tail = size;
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}
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}
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