mirror of
https://github.com/TheAlgorithms/Java.git
synced 2025-07-09 20:20:56 +08:00
Formatted with Google Java Formatter
This commit is contained in:
github-actions
@ -11,203 +11,201 @@ import java.util.stream.StreamSupport;
|
|||||||
* @param <E> the type that each index of the array will hold
|
* @param <E> the type that each index of the array will hold
|
||||||
*/
|
*/
|
||||||
public class DynamicArray<E> implements Iterable<E> {
|
public class DynamicArray<E> implements Iterable<E> {
|
||||||
private static final int DEFAULT_CAPACITY = 16;
|
private static final int DEFAULT_CAPACITY = 16;
|
||||||
|
|
||||||
private int capacity;
|
private int capacity;
|
||||||
private int size;
|
private int size;
|
||||||
private Object[] elements;
|
private Object[] elements;
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* constructor
|
* constructor
|
||||||
*
|
*
|
||||||
* @param capacity the starting length of the desired array
|
* @param capacity the starting length of the desired array
|
||||||
*/
|
*/
|
||||||
public DynamicArray(final int capacity) {
|
public DynamicArray(final int capacity) {
|
||||||
this.size = 0;
|
this.size = 0;
|
||||||
this.capacity = capacity;
|
this.capacity = capacity;
|
||||||
this.elements = new Object[this.capacity];
|
this.elements = new Object[this.capacity];
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/** No-args constructor */
|
||||||
* No-args constructor
|
public DynamicArray() {
|
||||||
*/
|
this(DEFAULT_CAPACITY);
|
||||||
public DynamicArray() {
|
}
|
||||||
this(DEFAULT_CAPACITY);
|
|
||||||
}
|
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* Adds an element to the array If full, creates a copy array twice the size of the current one
|
* Adds an element to the array If full, creates a copy array twice the size of the current one
|
||||||
*
|
*
|
||||||
* @param element the element of type <E> to be added to the array
|
* @param element the element of type <E> to be added to the array
|
||||||
*/
|
*/
|
||||||
public void add(final E element) {
|
public void add(final E element) {
|
||||||
if (this.size == this.elements.length) {
|
if (this.size == this.elements.length) {
|
||||||
this.elements = Arrays.copyOf(this.elements, newCapacity(2 * this.capacity));
|
this.elements = Arrays.copyOf(this.elements, newCapacity(2 * this.capacity));
|
||||||
}
|
}
|
||||||
|
|
||||||
this.elements[this.size] = element;
|
this.elements[this.size] = element;
|
||||||
size++;
|
size++;
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* Places element of type <E> at the desired index
|
* Places element of type <E> at the desired index
|
||||||
*
|
*
|
||||||
* @param index the index for the element to be placed
|
* @param index the index for the element to be placed
|
||||||
* @param element the element to be inserted
|
* @param element the element to be inserted
|
||||||
*/
|
*/
|
||||||
public void put(final int index, E element) {
|
public void put(final int index, E element) {
|
||||||
this.elements[index] = element;
|
this.elements[index] = element;
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* get method for element at a given index returns null if the index is empty
|
* get method for element at a given index returns null if the index is empty
|
||||||
*
|
*
|
||||||
* @param index the desired index of the element
|
* @param index the desired index of the element
|
||||||
* @return <E> the element at the specified index
|
* @return <E> the element at the specified index
|
||||||
*/
|
*/
|
||||||
public E get(final int index) {
|
public E get(final int index) {
|
||||||
return getElement(index);
|
return getElement(index);
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* Removes an element from the array
|
* Removes an element from the array
|
||||||
*
|
*
|
||||||
* @param index the index of the element to be removed
|
* @param index the index of the element to be removed
|
||||||
* @return <E> the element removed
|
* @return <E> the element removed
|
||||||
*/
|
*/
|
||||||
public E remove(final int index) {
|
public E remove(final int index) {
|
||||||
final E oldElement = getElement(index);
|
final E oldElement = getElement(index);
|
||||||
fastRemove(this.elements, index);
|
fastRemove(this.elements, index);
|
||||||
|
|
||||||
if (this.capacity > DEFAULT_CAPACITY && size * 4 <= this.capacity)
|
if (this.capacity > DEFAULT_CAPACITY && size * 4 <= this.capacity)
|
||||||
this.elements = Arrays.copyOf(this.elements, newCapacity(this.capacity / 2));
|
this.elements = Arrays.copyOf(this.elements, newCapacity(this.capacity / 2));
|
||||||
return oldElement;
|
return oldElement;
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* get method for size field
|
* get method for size field
|
||||||
*
|
*
|
||||||
* @return int size
|
* @return int size
|
||||||
*/
|
*/
|
||||||
public int getSize() {
|
public int getSize() {
|
||||||
return this.size;
|
return this.size;
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* isEmpty helper method
|
* isEmpty helper method
|
||||||
*
|
*
|
||||||
* @return boolean true if the array contains no elements, false otherwise
|
* @return boolean true if the array contains no elements, false otherwise
|
||||||
*/
|
*/
|
||||||
public boolean isEmpty() {
|
public boolean isEmpty() {
|
||||||
return this.size == 0;
|
return this.size == 0;
|
||||||
}
|
}
|
||||||
|
|
||||||
public Stream<E> stream() {
|
public Stream<E> stream() {
|
||||||
return StreamSupport.stream(spliterator(), false);
|
return StreamSupport.stream(spliterator(), false);
|
||||||
}
|
}
|
||||||
|
|
||||||
private void fastRemove(final Object[] elements, final int index) {
|
private void fastRemove(final Object[] elements, final int index) {
|
||||||
final int newSize = this.size - 1;
|
final int newSize = this.size - 1;
|
||||||
|
|
||||||
if (newSize > index) {
|
if (newSize > index) {
|
||||||
System.arraycopy(elements, index + 1, elements, index, newSize - index);
|
System.arraycopy(elements, index + 1, elements, index, newSize - index);
|
||||||
}
|
}
|
||||||
|
|
||||||
elements[this.size = newSize] = null;
|
elements[this.size = newSize] = null;
|
||||||
}
|
}
|
||||||
|
|
||||||
private E getElement(final int index) {
|
private E getElement(final int index) {
|
||||||
return (E) this.elements[index];
|
return (E) this.elements[index];
|
||||||
}
|
}
|
||||||
|
|
||||||
private int newCapacity(int capacity) {
|
private int newCapacity(int capacity) {
|
||||||
this.capacity = capacity;
|
this.capacity = capacity;
|
||||||
return this.capacity;
|
return this.capacity;
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* returns a String representation of this object
|
* returns a String representation of this object
|
||||||
*
|
*
|
||||||
* @return String a String representing the array
|
* @return String a String representing the array
|
||||||
*/
|
*/
|
||||||
@Override
|
@Override
|
||||||
public String toString() {
|
public String toString() {
|
||||||
return Arrays.toString(Arrays.stream(this.elements).filter(Objects::nonNull).toArray());
|
return Arrays.toString(Arrays.stream(this.elements).filter(Objects::nonNull).toArray());
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* Creates and returns a new Dynamic Array Iterator
|
* Creates and returns a new Dynamic Array Iterator
|
||||||
*
|
*
|
||||||
* @return Iterator a Dynamic Array Iterator
|
* @return Iterator a Dynamic Array Iterator
|
||||||
*/
|
*/
|
||||||
@Override
|
@Override
|
||||||
public Iterator iterator() {
|
public Iterator iterator() {
|
||||||
return new DynamicArrayIterator();
|
return new DynamicArrayIterator();
|
||||||
}
|
}
|
||||||
|
|
||||||
private class DynamicArrayIterator implements Iterator<E> {
|
private class DynamicArrayIterator implements Iterator<E> {
|
||||||
|
|
||||||
private int cursor;
|
private int cursor;
|
||||||
|
|
||||||
@Override
|
@Override
|
||||||
public boolean hasNext() {
|
public boolean hasNext() {
|
||||||
return this.cursor != size;
|
return this.cursor != size;
|
||||||
}
|
}
|
||||||
|
|
||||||
@Override
|
@Override
|
||||||
public E next() {
|
public E next() {
|
||||||
if (this.cursor > DynamicArray.this.size) throw new NoSuchElementException();
|
if (this.cursor > DynamicArray.this.size) throw new NoSuchElementException();
|
||||||
|
|
||||||
if (this.cursor > DynamicArray.this.elements.length)
|
if (this.cursor > DynamicArray.this.elements.length)
|
||||||
throw new ConcurrentModificationException();
|
throw new ConcurrentModificationException();
|
||||||
|
|
||||||
final E element = DynamicArray.this.getElement(this.cursor);
|
final E element = DynamicArray.this.getElement(this.cursor);
|
||||||
this.cursor++;
|
this.cursor++;
|
||||||
|
|
||||||
return element;
|
return element;
|
||||||
}
|
}
|
||||||
|
|
||||||
@Override
|
@Override
|
||||||
public void remove() {
|
public void remove() {
|
||||||
if (this.cursor < 0) throw new IllegalStateException();
|
if (this.cursor < 0) throw new IllegalStateException();
|
||||||
|
|
||||||
DynamicArray.this.remove(this.cursor);
|
DynamicArray.this.remove(this.cursor);
|
||||||
this.cursor--;
|
this.cursor--;
|
||||||
}
|
}
|
||||||
|
|
||||||
@Override
|
@Override
|
||||||
public void forEachRemaining(Consumer<? super E> action) {
|
public void forEachRemaining(Consumer<? super E> action) {
|
||||||
Objects.requireNonNull(action);
|
Objects.requireNonNull(action);
|
||||||
|
|
||||||
for (int i = 0; i < DynamicArray.this.size; i++) {
|
for (int i = 0; i < DynamicArray.this.size; i++) {
|
||||||
action.accept(DynamicArray.this.getElement(i));
|
action.accept(DynamicArray.this.getElement(i));
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* This class is the driver for the DynamicArray<E> class it tests a variety of methods and prints
|
* This class is the driver for the DynamicArray<E> class it tests a variety of methods and prints
|
||||||
* the output
|
* the output
|
||||||
*/
|
*/
|
||||||
public static void main(String[] args) {
|
public static void main(String[] args) {
|
||||||
DynamicArray<String> names = new DynamicArray<>();
|
DynamicArray<String> names = new DynamicArray<>();
|
||||||
names.add("Peubes");
|
names.add("Peubes");
|
||||||
names.add("Marley");
|
names.add("Marley");
|
||||||
|
|
||||||
for (String name : names) {
|
for (String name : names) {
|
||||||
System.out.println(name);
|
System.out.println(name);
|
||||||
}
|
}
|
||||||
|
|
||||||
names.stream().forEach(System.out::println);
|
names.stream().forEach(System.out::println);
|
||||||
|
|
||||||
System.out.println(names);
|
System.out.println(names);
|
||||||
|
|
||||||
System.out.println(names.getSize());
|
System.out.println(names.getSize());
|
||||||
|
|
||||||
names.remove(0);
|
names.remove(0);
|
||||||
|
|
||||||
for (String name : names) {
|
for (String name : names) {
|
||||||
System.out.println(name);
|
System.out.println(name);
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|||||||
Reference in New Issue
Block a user