/**
* @author mcrwayfun
* @version v1.0
* @date Created in 2018/10/01
* @description
*/
public class Array {
// ä¿å˜å…ƒç´ 使用的数组
private E[] data;
// 数组ä¸å…ƒç´ 的个数
private int size;
@SuppressWarnings("unchecked")
public Array(int capacity) {
data = (E[]) new Object[capacity];
this.size = 0;
}
public Array() {
this(10);
}
// 获å–容é‡
public int getCapacity() {
return data.length;
}
// 获å–当å‰æ•°ç»„å…ƒç´
public int getSize() {
return size;
}
// 判æ–数组是å¦ä¸ºç©º
public boolean isEmpty() {
return size == 0;
}
// å‘æ•°ç»„çš„æœ«å°¾æ·»åŠ å…ƒç´
void addLast(E e) {
add(size, e);
}
// å‘æ•°ç»„çš„å¤´éƒ¨æ·»åŠ å…ƒç´
void addFirst(E e) {
add(0, e);
}
// 在指定ä½ç½®æ·»åŠ å…ƒç´
void add(int index, E e) {
if (index < 0 || index > size)
throw new IllegalArgumentException("Add failed.index is invalid !");
if (size == data.length)
resize(2 * data.length);// 扩容两å€
for (int i = size - 1; i >= index; i--)
data[i + 1] = data[i];
data[index] = e;
size++;
}
// 获å–指定ä½ç½®çš„å…ƒç´
public E get(int index) {
if (index < 0 || index >= size)
throw new IllegalArgumentException("Add failed.index is invalid !");
return data[index];
}
// 获å–头部元ç´
public E getFirst() {
return get(0);
}
// 获å–尾部元ç´
public E getLast() {
return get(size - 1);
}
// 替æ¢æŒ‡å®šä½ç½®çš„å…ƒç´
public void set(int index, E e) {
if (index < 0 || index >= size)
throw new IllegalArgumentException("Set failed.index is invalid !");
data[index] = e;
}
// 判æ–数组ä¸æ˜¯å¦åŒ…å«è¯¥å…ƒç´
public boolean contains(E e) {
for (E x : data) {
if (x.equals(e)) {
return true;
}
}
return false;
}
// æŸ¥æ‰¾å…ƒç´ e在数组ä¸å¯¹åº”的索引，如果ä¸å˜åœ¨åˆ™è¿”回 -1
public int find(E e) {
for (int i = 0; i < size; i++)
if (data[i].equals(e))
return i;
return -1;
}
// åˆ é™¤æ•°ç»„ä¸æŒ‡å®šç´¢å¼•çš„å…ƒç´
public E remove(int index) {
if (index < 0 || index >= size)
throw new IllegalArgumentException("Remove failed.index is invalid !");
E ret = data[index];
for (int i = index + 1; i <= size - 1; i++)
data[i - 1] = data[i];
size--;
data[size] = null;// help gc
if (size == data.length / 4 && data.length / 2 != 0)
resize(data.length / 2);// 容é‡ç¼©å‡ä¸ºä¸€åŠ
return ret;
}
// 从数组ä¸åˆ 除最åŽä¸€ä¸ªå…ƒç´
public E removeLast() {
return remove(size - 1);
}
// 从数组ä¸åˆ é™¤å…ƒç´ e
public E removeFirst() {
return remove(0);
}
// åˆ é™¤æ•°ç»„ä¸æŒ‡å®šçš„å…ƒç´ e
public void removeElement(E e) {
int index = find(e);
if (index != -1)
remove(index);
}
@Override
public String toString() {
StringBuilder res = new StringBuilder();
res.append(String.format("Array: size = %d , capacity = %d\n", size, data.length));
res.append('[');
for (int i = 0; i < size; i++) {
res.append(data[i]);
if (i != size - 1)
res.append(", ");
}
res.append(']');
return res.toString();
}
// 将数组容é‡æ”¹ä¸ºnewCapacity大å°
@SuppressWarnings("unchecked")
private void resize(int newCapacity) {
E[] newData = (E[]) new Object[newCapacity];
for (int i = 0; i < size; i++)
newData[i] = data[i];
data = newData;
}
}