数据结构--Arraylist的实现

[java]代码库

1.主程序
package s1210Arraylist队列;

public class Arraylist implements List {
	private Object[] data = new Object[0];

	public void add(Object x) {
		Object[] data2 = new Object[data.length + 1];
		if (data.length >= 1) {
			for (int i = 0; i < data.length; i++) {
				data2[i] = data[i];
			}
		}

		data2[data.length] = x;
		data = data2;
	}

	public Object remove(int y) {
		if (y < 0 || y >= data.length) {
			System.out.println("数组越界了");
			return null;
		}

		else {
			Object[] data2 = new Object[data.length - 1];
			for (int i = 0; i < y; i++)
				data2[i] = data[i];
			for (int i = y + 1; i < data.length; i++)
				data2[i - 1] = data[i];
			Object t;
			t = data[y];
			data = data2;
			return t;
		}
	}

	public void insert(Object x, int y) {
		if (y < 0 || y > data.length) {
			System.out.println("数组越界了");
		} else {
			Object[] data2 = new Object[data.length + 1];
			data2[y - 1] = x;
			for (int i = 0; i < y - 1; i++)
				data2[i] = data[i];
			for (int i = y - 1; i < data.length; i++)
				data2[i + 1] = data[i];

			data = data2;
		}

	}

	public Object get(int x) {
		return data[x];
	}

	public int size() {
		return data.length;
	}
}



2.List接口
package s1210Arraylist队列;

public interface List  {

       public void add(Object x);
       public Object remove(int x);
       public void insert(Object x,int y);
       public int size();
       public Object get(int x);
}


3.测试类
package s1210Arraylist队列;

public class Text {

	public static void main(String[] args) {
	      List s=new Arraylist();
	
	      for(int i=0;i<10;i++)
	      { s.add("str"+i);}
	      
	      System.out.println();
	      
	      s.insert("str11",3);
	      System.out.println("size="+s.size());
	      
	      for(int i=0;i<s.size();i++)
	      {System.out.println(s.get(i));}
	}

}