diff --git a/group02/562768642/src/com/github/orajavac/coding2017/basic/LinkedList.java b/group02/562768642/src/com/github/orajavac/coding2017/basic/LinkedList.java
index 3cc762aeff..ec8fd7a4a7 100644
--- a/group02/562768642/src/com/github/orajavac/coding2017/basic/LinkedList.java
+++ b/group02/562768642/src/com/github/orajavac/coding2017/basic/LinkedList.java
@@ -2,142 +2,131 @@
 
 public class LinkedList implements List,Iterator {
 	
-	private Node head;
-
-	private Node current;
+	public Node head;
 	
 	private int size=0;
 	
-	public void add(Object o){
-		Node n = new Node();
-		n.next=this.head;
-		n.data=o;
-		this.head=n;
+	private static class Node{
+		Object data;
+		Node next;	
 	}
-	public void add(int index , Object o){
-		
+	
+	public Iterator iterator(){
+		return null;
+	}
+	
+	public boolean hasNext(){
+		return false;
+	}
+	
+	public Object next(){
+		return null;
+	}
+	
+	public void add(Object o){
+		if (head == null){
+			head = new Node();
+			Node n = new Node();
+			n.data = o;
+			head.next = n;
+			size++;
+			head.data=size;
+		}else{
+			Node e = head.next;
+			while (e.next!=null){
+				e=e.next;
+			}
+			Node n = new Node();
+			n.data = o;
+			e.next=n;
+			size++;
+			head.data=size;
+		}
 	}
+	
 	public Object get(int index){
-		Node c = this.head;
+		int len=Integer.parseInt(head.data.toString());
+		if (index>len||index<=0){
+			throw new RuntimeException("下标不存在"+index);
+		}
+		Node e = head;
 		int i=0;
-		while(c!=null){
+		while (e.next != null){
 			i++;
-			if (index==i){
-				return c.data;
+			if (i == index){
+				return e.next.data;
 			}
-			c=c.next;
+			e=e.next;
 		}
 		return null;
 	}
+	
 	public Object remove(int index){
-		int s=size();
-		if (s==index){
-			Node n=head.next;
-			head=n;
-			return null;
+		int len=Integer.parseInt(head.data.toString());
+		if (index>len||index<=0){
+			throw new RuntimeException("下标不存在"+index);
 		}
-		Node n=head;
-		Node p = null;
-		while (n!=null){
-			s--;
-			if (s==index){
-				p=n.next;			
-				n.next=p.next;
-				break;
+		Node e = head;
+		Object data = null;
+		int i=0;
+		while (e.next != null){
+			i++;
+			if (i == index){
+				len--;
+				head.data = len;
+				data = e.next.data;
+				e.next = e.next.next;
+				return data;
 			}
-			n=n.next;
+			e=e.next;
 		}
 		return null;
 	}
 	
-	public void listNode(){
-		Node c = this.head;
-		while(c!=null){
-			System.out.print(c.data+ " -> ");
-			c=c.next;
-		}
-		System.out.println();
+	public Object removeFirst(){
+		return remove(1);
 	}
 	
-	public int size(){
-		size=0;
-		Node c = this.head;
-		while(c!=null){
-			size++;
-			c=c.next;
-		}
-		return size;
+	public Object removeLast(){
+		return remove(Integer.parseInt(head.data.toString()));
 	}
 	
 	public void addFirst(Object o){
-		if (this.head==null){
-			this.head = new Node();
-			this.head.data=o;
-		}else{
-			Node f = new Node();
-			Node n=head;
-			Node p=null;
-			while (n!=null){
-				p=n;
-				n=n.next;
-			}
-			f.data=o;
-			p.next=f;
-		}
+		Node e = head.next;
+		Node n = new Node();
+		n.data=o;
+		n.next=e;
+		size++;
+		head.next=n;
+		head.data=size;
 	}
+	
 	public void addLast(Object o){
 		add(o);
 	}
-	public Object removeFirst(){
-		remove(1);
-		return null;
-	}
-	public Object removeLast(){
-		remove(size());
-		return null;
-	}
 	
-	public Iterator iterator(){
-		LinkedList l = new LinkedList();
-		l.head=this.head;
-		return l;
+	public int size(){
+		return Integer.parseInt(head.data.toString());
 	}
 	
-	public boolean hasNext(){
-		current = head;
-		if (current!=null){
-			head = current.next;
-			return true;
+	public void listNode(){
+		Node n = head;
+		StringBuffer buffer = new StringBuffer();
+		while (n.next!=null){
+			buffer.append(n.next.data + " -> ");
+			n=n.next;
+		}
+		if(buffer.length()>0){
+			System.out.print(buffer.substring(0,buffer.length()-3));
+			System.out.println();
 		}
-		return false;
-	}
-	
-	public Object next(){
-		return current.data;
-	}
-	
-	
-	private static  class Node{
-		Object data;
-		Node next;
-		
 	}
 	
 	/**
 	 * 把该链表逆置
 	 * 例如链表为 3->7->10 , 逆置后变为  10->7->3
 	 */
-	public  void reverse(){		
-		
-	}
-	
-	/**
-	 * 删除一个单链表的前半部分
-	 * 例如：list = 2->5->7->8 , 删除以后的值为 7->8
-	 * 如果list = 2->5->7->8->10 ,删除以后的值为7,8,10
-
-	 */
-	public  void removeFirstHalf(){
+	public void reverse(){		
 		
 	}
 	
@@ -146,9 +135,33 @@ public  void removeFirstHalf(){
 	 * @param i
 	 * @param length
 	 */
-	public  void remove(int i, int length){
-		
+	public void remove(int i, int length){
+		if (i <= 0 || length<=0){
+			throw new RuntimeException("起始值、结束值都不能小于0等于");
+		}
+		int len = length + i;
+		if (len > size){
+			throw new RuntimeException("删除索引长度超过了链表长度");
+		}
+		Node e = head;
+		int y = 0;
+		while (e.next != null){
+			y++;
+			if (y == i){
+				Node n = e.next;
+				while (n!=null){
+					n = n.next;
+					if (y == length){
+						break;
+					}
+					y++;
+					n=n.next;
+				}
+			}
+			e=e.next;
+		}
 	}
+	
 	/**
 	 * 假定当前链表和list均包含已升序排列的整数
 	 * 从当前链表中取出那些list所指定的元素
@@ -157,8 +170,40 @@ public  void remove(int i, int length){
 	 * 返回的结果应该是[101,301,401,601]  
 	 * @param list
 	 */
-	public static int[] getElements(LinkedList list){
-		return null;
+	public int[] getElements(LinkedList list){
+		if (list==null||list.head==null){
+			throw new RuntimeException("集合没有初始化");
+		}
+		int[] elements = new int[Integer.parseInt(list.head.data.toString())];
+		Node l = list.head;
+		Node n = head;
+		int len = 0;
+		int i = 0;
+		while (l.next!=null){
+			len = 0;
+			n=head;
+			while(n.next!=null){
+				len++;
+				if(len==Integer.parseInt(l.next.data.toString())){
+					elements[i]=Integer.parseInt(n.next.data.toString());
+					i++;
+					break;
+				}
+				n=n.next;
+			}
+			l = l.next;
+		}
+		return elements;
+	}
+	
+	/**
+	 * 删除一个单链表的前半部分
+	 * 例如：list = 2->5->7->8 , 删除以后的值为 7->8
+	 * 如果list = 2->5->7->8->10 ,删除以后的值为7,8,10
+
+	 */
+	public  void removeFirstHalf(){
+		
 	}
 	
 	/**
@@ -168,26 +213,61 @@ public static int[] getElements(LinkedList list){
 	 * @param list
 	 */
 	
-	public  void subtract(LinkedList list){
-		
+	public void subtract(LinkedList list){
+		if (list==null||list.head==null){
+			throw new RuntimeException("集合没有初始化");
+		}
+		Node l = list.head;
+		Node n = head;
+		int i = 0;
+		while (l.next!=null){
+			n=head;
+			i=0;
+			while(n.next!=null){
+				i++;
+				if(n.next.data.equals(l.next.data)){
+					remove(i);
+					break;
+				}
+				n=n.next;
+			}
+			l = l.next;
+		}
 	}
 	
 	/**
 	 * 已知当前链表中的元素以值递增有序排列，并以单链表作存储结构。
 	 * 删除表中所有值相同的多余元素（使得操作后的线性表中所有元素的值均不相同）
 	 */
-	public  void removeDuplicateValues(){
+	public void removeDuplicateValues(){
 		
 	}
 	
 	/**
 	 * 已知链表中的元素以值递增有序排列，并以单链表作存储结构。
 	 * 试写一高效的算法，删除表中所有值大于min且小于max的元素（若表中存在这样的元素）
+	 * 11->101->201->301->401->501->601->701
 	 * @param min
 	 * @param max
 	 */
-	public  void removeRange(int min, int max){
-		
+	public void removeRange(int min, int max){
+		if (min<=0||max<=0||min>max){
+			throw new RuntimeException("录入不正确："+min+","+max+" 应该大于min且小于max的元素");
+		}
+		Node n = head;
+		int data = 0;
+		Node p = null;
+		while(n.next != null){
+			data=Integer.parseInt(n.next.data.toString());	//11
+			if(data>min&&data<max){
+				p = n.next.next;	//101
+				n.next = p;
+				size--;
+			}else{
+				n = n.next;
+			}
+		}
+		head.data=size;
 	}
 	
 	/**
@@ -196,7 +276,12 @@ public  void removeRange(int min, int max){
 	 * @param list
 	 */
 	public  LinkedList intersection( LinkedList list){
-		return null;
+		return null; 
+	}
+
+	public void add(int index, Object o) {
+		// TODO Auto-generated method stub
+		
 	}
 	
 }