MyArrayList

group14/857999411/MyArrayList/.classpath

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+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

group14/857999411/MyArrayList/.gitignore

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+/bin/

group14/857999411/MyArrayList/.project

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+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>MyArrayList</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

group14/857999411/MyArrayList/.settings/org.eclipse.jdt.core.prefs

@@ -0,0 +1,11 @@
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.source=1.8

group14/857999411/MyArrayList/src/MyArrayList.java

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+import java.util.*;
+
+
+
+class SimpleArrayList
+{
+	//����Object�������飬
+	//��������Ԫ�ظ���
+	private Object [] elementData;
+	private int size;
+
+	//�޲ι��캯����Ĭ�����ɳ���Ϊ10������
+	SimpleArrayList ()
+	{
+		this(10);
+	}
+
+	//�������캯�����������ָ�������С
+	SimpleArrayList (int initialCapacity)
+	{
+		if(initialCapacity < 0)
+			throw new IllegalArgumentException("IllegalArgumentException : �Ƿ�����");
+		 elementData =new Object [initialCapacity];
+
+	}
+
+	//����ָ��λ�õ�Ԫ��
+	public void add (int index,Object element)
+	{
+		if(index > size || index < 0)
+			throw new IndexOutOfBoundsException("IndexOutOfBoundsException �������±�Խ��");
+		ensureCapacity(size+1);
+		//����ָ��λ��Ԫ��ʱ
+		//����λ�ú������Ԫ������
+		System.arraycopy(elementData,index,elementData,index+1,size-index);
+		elementData[index] =element;
+		size++;
+	}
+
+	//�ɵ������������
+	public void ensureCapacity (int mincapacity)
+	{
+		int oldlen =elementData.length;
+		if(mincapacity > oldlen)
+		{
+			int newlen =(oldlen * 3)/2 + 1;
+				if(mincapacity > newlen)
+					newlen =mincapacity;
+			elementData =Arrays.copyOf(elementData,newlen);
+		}
+	}
+
+	public int size ()
+	{
+		return size;
+	}
+
+	//��ȡָ��λ�õ�Ԫ��
+	public Object get(int index)
+	{
+		rangeCheck(index);
+		return elementData[index];
+	}
+
+	//ArrayList��������null����˷��������������
+	public boolean remove (Object element)
+	{
+		if(element == null)
+		{
+			for(int i=0; i < size; i++)
+			{
+				if(elementData[i] == null)
+					fastRemove(i);
+				return true;
+			}
+		}else{
+				for(int i=0; i < size; i++)
+					if(element.equals(elementData[i]))
+						fastRemove(i);
+				return true;
+		}
+		return false;
+
+	}
+
+	//�������жϱ߽�Ĵ��������ҵ�ƥ��Ԫ��ʱ���ô˷�����
+	public void fastRemove (int index)
+	{
+		int numMoved = size-index-1;
+			if(numMoved > 0)
+				System.arraycopy(elementData,index+1,elementData,index,numMoved);
+			elementData[--size] = null;
+
+	}
+
+	public void clear()
+	{
+		elementData = null;
+	}
+
+	//�жϴ���IJ����Ƿ�Խ��
+	public void rangeCheck (int index)
+	{
+		if(index >=size || index < 0)
+			throw new IndexOutOfBoundsException("IndexOutOfBoundsException �������±�Խ��");
+	}
+
+	public boolean isEmpty ()
+	{
+		return size == 0;
+	}
+
+}
+
+public class  MyArrayList
+{
+	public static void main(String[] args) 
+	{
+
+		SimpleArrayList sa =new SimpleArrayList();
+		sa.add(0,"java001");
+		sa.add(1,"java002");
+		sa.add(2,"java003");
+		sa.add(3,"java004");
+
+		//System.out.println(sa.get(1));
+
+		for(int i=0; i<sa.size(); i++)
+		{
+			System.out.print(sa.get(i));
+		}
+
+		System.out.println(sa.remove("java003"));
+
+		for(int i=0; i<sa.size(); i++)
+		{
+			System.out.print(sa.get(i));
+		}
+
+	}
+}
+