Merge pull request #6 from EsMussSeinbo/master

1501 bo

group15/1501_2535894075/2017code/src/arraylist.java

@@ -0,0 +1,252 @@
+package firstweek;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+import java.util.ListIterator;
+
+public class arraylist implements List {
+	ArrayList<Integer> q=new ArrayList<Integer>();
+
+	private static final int InitialValue=10;
+
+	private static final Object[] Empty_Elementdata={};	
+
+	private Object[] elementData = new Object[100];
+
+	private int size = 0;
+
+	public boolean add(Object o){
+		if(elementData==Empty_Elementdata){
+			//设置为初始化容量为10的数组
+			elementData[0]=o;
+		}
+		if(size==elementData.length){
+			//copy数组并增大50%
+			int oldLength=elementData.length;
+			int newLength=oldLength+(oldLength>>1);
+			if(newLength-oldLength>0){
+				elementData=Arrays.copyOf(elementData, newLength);
+			}
+		}
+		elementData[size++]=o;
+		return true;
+
+	}
+	public void add(int index, Object o){
+		if(elementData==Empty_Elementdata){
+			elementData[0]=o;
+			System.out.print("创建了一个新的只有该元素的数组");
+			return ;
+		}
+		if(size==elementData.length){
+			int oldLength=elementData.length;
+			int newLength=oldLength+(oldLength>>1);
+			if(newLength-oldLength>0){
+				System.arraycopy(elementData, index, elementData,index+1 ,size-index);
+			}
+		}
+		elementData[index]=o;
+		size++;
+	}
+
+	public Object get(int index){
+		rangecheck(index);		
+		return elementData[index];
+	}
+
+	public Object remove(int index){
+		rangecheck(index);
+		Object oldValue=elementData(index);
+		int numMove=size-index-1;
+		if(numMove>0){
+			System.arraycopy(elementData, index+1, elementData, index, numMove);
+		}
+		elementData[--size]=null;
+		return true;
+	}
+	public boolean removeObject(Object o){
+		if(o==null){
+			for(int index=0;index<size;index++){
+				if(elementData[index]==null){
+					fastremove(index);
+					return true;
+				}
+			}
+		}else{
+			for(int index=0;index<size;index++){
+				if(o.equals(elementData[index])){
+					fastremove(index);
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	private ArrayList<Integer> elementData(int index) {
+		// TODO Auto-generated method stub
+		return null;
+	}
+	public int size(){
+		return size;
+	}
+	@Override
+	public boolean isEmpty() {
+		// TODO Auto-generated method stub
+		return size==0;
+	}
+	@Override
+	public boolean contains(Object o) {
+		// TODO Auto-generated method stub
+		return 0>=indexOf(o);
+	}
+	@Override
+	public Iterator iterator() {
+		// TODO Auto-generated method stub
+		//不会
+		return null;
+	}
+	@Override
+	public Object[] toArray() {
+		// TODO Auto-generated method stub
+		return Arrays.copyOf(elementData,size);
+	}
+	@Override
+	public Object[] toArray(Object[] a) {
+
+		// TODO Auto-generated method stub
+		return null;
+	}
+	@Override
+	public boolean remove(Object o) {
+		// TODO Auto-generated method stub
+		if(o==null){
+			for(int i=0;i<elementData.length;i++){
+				if(elementData[i]==null){
+					fastremove(i);
+					return true;
+				}
+			}
+		}else{
+			for(int i=0;i<elementData.length;i++){
+				if(o.equals(elementData[i])){
+					fastremove(i);
+					return true;
+				}
+			}
+		}
+
+		return false;
+	}
+	@Override
+	public boolean containsAll(Collection c) {
+		// TODO Auto-generated method stub
+		return false;
+	}
+	@Override
+	public boolean addAll(Collection c) {
+		// TODO Auto-generated method stub
+		return false;
+	}
+	@Override
+	public boolean addAll(int index, Collection c) {
+		// TODO Auto-generated method stub
+		return false;
+	}
+	@Override
+	public boolean removeAll(Collection c) {
+		// TODO Auto-generated method stub
+		return false;
+	}
+	@Override
+	public boolean retainAll(Collection c) {
+		// TODO Auto-generated method stub
+		return false;
+	}
+	@Override
+	public void clear() {
+		// TODO Auto-generated method stub
+		for(int i=0;i<elementData.length;i++){
+			elementData[i]=null;
+		}
+		size=0;
+
+	}
+	@Override
+	public Object set(int index, Object element) {
+		// TODO Auto-generated method stub
+		if(index>size||index<0){
+			System.out.println("查询超出范围。");
+			return null;
+		}
+		elementData[index]=element;
+		return null;
+	}
+	@Override
+	public int indexOf(Object o) {
+		// TODO Auto-generated method stub
+		if(o==null){
+			for(int i=0;i<elementData.length;i++){
+				if(elementData[i]==null){
+					return i;
+				}
+			}
+		}else{
+			for(int i=0;i<elementData.length;i++){
+				if(o.equals(elementData[i])){
+					return i;
+				}
+			}
+		}
+
+		return 0;
+	}
+	@Override
+	public int lastIndexOf(Object o) {
+		// TODO Auto-generated method stub
+		int Storage=0;
+		boolean temp=false;
+		for(int i=0;i<size;i++){
+			if(o.equals(elementData[i])){
+				Storage=i;
+				temp=true;
+			}
+		}
+		if(temp){
+			return Storage;
+		}
+		return -1;
+	}
+	@Override
+	public ListIterator listIterator() {
+		// TODO Auto-generated method stub
+		return null;
+	}
+	@Override
+	public ListIterator listIterator(int index) {
+		// TODO Auto-generated method stub
+		return null;
+	}
+	@Override
+	public List subList(int fromIndex, int toIndex) {
+		// TODO Auto-generated method stub
+		return null;
+	}
+	private void rangecheck(int index){
+		if (index < 0 || index >= this.size)
+            throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
+	}
+	private String outOfBoundsMsg(int index) {
+            return "Index: "+index+", Size: "+this.size;
+	}
+	private void fastremove(int index){
+		int numMoved=size-index-1;
+		if(numMoved>0){
+			System.arraycopy(elementData, index+1, elementData, index, numMoved);
+		}
+		elementData[--size]=null;
+	}
+
+}