博客

import java.util.Arrays;

/**

* 设计一个泛型类orderedCollection，它存储的Comparable对象的集合（在数组中），

* 以及该集合的当前大小。提供public方法isEmpty，makeEmpty，insert，remove，findMin和

* findMax。finfMin和findMax分别返回该集合中最小的和最大T对象的引用（如果该集合为空，则返回null）

* @author wulei

*

* @param <E>

*/

public class CollectionTest<E> {

private Comparable[] elementData;

public void setElementData(Comparable[] obj){


this.elementData = obj;

}

public Comparable[] getElementData(){


return elementData;

}

public boolean isEmpty(){


return elementData.length == 0;

}

/**

* makeEmpty与List的clear()方法类似，Collection不为null,但是元素个数为0

*/

public void makeEmpty(){


elementData = new Comparable[]{};

}

public void insert(Comparable obj){


int length = elementData.length;

Comparable[] temp = new Comparable[length+1];

System.arraycopy(elementData, 0, temp, 0, length);

temp[length] = obj;

elementData = temp;

}

public void remove(int index){


if(index < 0 || elementData == null){


return ;

}

int length = elementData.length;

if((length-1) < index){


return ;

}

Comparable[] temp = new Comparable[length-1];

System.arraycopy(elementData, 0, temp, 0, index);

System.arraycopy(elementData, index+1, temp, index, length-index-1);

elementData = temp;

}

public void remove(E obj){


if(elementData == null || obj == null){


return;

}

int length = elementData.length;

for (int i = 0; i < length; i++) {


if(elementData[i] != null && elementData[i] == obj){


Comparable[] temp = new Comparable[length-1];

System.arraycopy(elementData, 0, temp, 0, i);

System.arraycopy(elementData, i+1, temp, i, length-i-1);

elementData = temp;

break;

}

}

}

public boolean isPresent(E obj){


if(elementData == null || obj == null){


return false;

}

boolean flag = false;

for (int i = 0; i < elementData.length; i++) {


if(null != elementData[i] && obj == elementData[i]){


flag = true;

break;

}

}

return flag;

}

public Comparable<E> findMin() {


if(elementData == null || elementData.length == 0){


return null;

}

int index = 0;

for (int i = 0; i < elementData.length; i++) {


if(elementData[i].compareTo(elementData[index]) < 0){


index = i;

}

}

return elementData[index];

}

public Comparable<E> findMax(){


if(elementData == null || elementData.length == 0){


return null;

}

int index = 0;

for (int i = 0; i < elementData.length; i++) {


if(elementData[i].compareTo(elementData[index]) > 0){


index = i;

}

}

return elementData[index];

}

public static void main(String[] args){


int i =0;

CollectionTest<String> collectionTest = new CollectionTest<String>();

Comparable[] objects =new Comparable[]{“9”};

collectionTest.setElementData(objects);

collectionTest.insert(“1”);

collectionTest.insert(“2”);

collectionTest.insert(“3”);

collectionTest.insert(“4”);

System.err.println(Arrays.toString(collectionTest.getElementData()));

collectionTest.remove(0);

System.err.println(Arrays.toString(collectionTest.getElementData()));

collectionTest.remove(“2”);

System.err.println(Arrays.toString(collectionTest.getElementData()));

boolean flag = collectionTest.isEmpty();

System.err.println(“isEmpty： “+flag);

boolean flag1 = collectionTest.isPresent(“1”);

System.err.println(“isPresent： “+flag1);

//collectionTest.makeEmpty();

boolean flag2 = collectionTest.isEmpty();

System.err.println(“isEmpty： “+flag2);

System.err.println(“min： “+collectionTest.findMin());

System.err.println(“max： “+collectionTest.findMax());

}

}