diff --git a/group27/514302761/src/com/company/ArrayList.java b/group27/514302761/src/com/company/ArrayList.java
new file mode 100644
index 0000000000..0ca210c919
--- /dev/null
+++ b/group27/514302761/src/com/company/ArrayList.java
@@ -0,0 +1,75 @@
+package com.company;
+
+import java.util.Arrays;
+
+public class ArrayList implements List {
+	
+	private int size = 0;
+	
+	private Object[] elementData = new Object[100];
+
+	public void add(Object o){
+		if(size+1>elementData.length){
+			elementData= Arrays.copyOf(elementData,elementData.length/3*2);
+		}
+		elementData[size++]=o;
+	}
+	public void add(int index, Object o){
+		if(index<0||index>size){
+			throw new IndexOutOfBoundsException();
+		}
+		if(size+1>elementData.length){
+			elementData=Arrays.copyOf(elementData,elementData.length/3*2);
+		}
+		System.arraycopy(elementData,index,elementData,index+1,size-index);
+		elementData[index]=o;
+		size++;
+	}
+
+
+	public Object get(int index){
+		if(index<0||index>=size){
+			throw new IndexOutOfBoundsException();
+		}
+		return elementData[index];
+	}
+	
+	public Object remove(int index){
+		Object old=elementData[index];
+		System.arraycopy(elementData,index+1,elementData,index,size-1-index);
+		size--;
+		return old;
+	}
+	
+	public int size(){
+		for(int i=0;i<elementData.length;i++){
+			if(null==elementData[i]){
+				size=i;
+				break;
+			}
+		}
+		return size;
+	}
+	
+	public Iterator iterator(){
+		return new ArrayListIterator();
+	}
+
+	public class ArrayListIterator implements Iterator{
+
+
+		private int currentIndex=0;
+		@Override
+		public boolean hasNext() {
+
+			return currentIndex<size();
+		}
+
+		@Override
+		public Object next() {
+			Object o=get(currentIndex);
+			currentIndex++;
+			return o;
+		}
+	}
+}
diff --git a/group27/514302761/src/com/company/BinaryTreeNode.java b/group27/514302761/src/com/company/BinaryTreeNode.java
new file mode 100644
index 0000000000..c4a70a3af6
--- /dev/null
+++ b/group27/514302761/src/com/company/BinaryTreeNode.java
@@ -0,0 +1,59 @@
+package com.company;
+
+public class BinaryTreeNode {
+	
+	private Comparable data;
+	private BinaryTreeNode left;
+	private BinaryTreeNode right;
+
+	public Object getData() {
+		return data;
+	}
+	public void setData(Object data) {
+		this.data = (Comparable) data;
+	}
+	public BinaryTreeNode getLeft() {
+		return left;
+	}
+	public void setLeft(BinaryTreeNode left) {
+		this.left = left;
+	}
+	public BinaryTreeNode getRight() {
+		return right;
+	}
+	public void setRight(BinaryTreeNode right) {
+		this.right = right;
+	}
+	
+	public BinaryTreeNode insert(Comparable  o){
+		BinaryTreeNode insercode=new BinaryTreeNode();
+		BinaryTreeNode compareNode=this;
+			insercode.setData(o);
+	while (null!=compareNode){
+		if(null==compareNode.getData()){
+			compareNode.setData(o);
+			break;
+		}else{
+			Comparable com= (Comparable) compareNode.getData();
+			int result=com.compareTo(o);
+			if(result==0){
+				break;
+			}else if (result>0){
+			if(null==compareNode.getLeft()){
+				compareNode.setLeft(insercode);
+				break;
+			}
+                compareNode=compareNode.getLeft();
+			}else if(result<0){
+			    if(null==compareNode.getRight()){
+                    compareNode.setRight(insercode);
+                    break;
+                }
+                compareNode=compareNode.getLeft();
+            }
+		}
+	}
+		return  insercode;
+	}
+	
+}
diff --git a/group27/514302761/src/com/company/Iterator.java b/group27/514302761/src/com/company/Iterator.java
new file mode 100644
index 0000000000..2e93f47bc2
--- /dev/null
+++ b/group27/514302761/src/com/company/Iterator.java
@@ -0,0 +1,7 @@
+package com.company;
+
+public interface Iterator {
+	public boolean hasNext();
+	public Object next();
+
+}
diff --git a/group27/514302761/src/com/company/LinkedList.java b/group27/514302761/src/com/company/LinkedList.java
new file mode 100644
index 0000000000..4a5d8da88b
--- /dev/null
+++ b/group27/514302761/src/com/company/LinkedList.java
@@ -0,0 +1,249 @@
+package com.company;
+
+
+import java.util.NoSuchElementException;
+
+public class LinkedList implements List {
+	
+	private Node head;
+	
+	public void add(Object o){
+		if(null==head){
+			head=new Node();
+			head.data=o;
+		}else {
+		    Node node=head;
+		    while (null!=node.next){
+		        node=node.next;
+            }
+         Node addNode=new Node();
+		    addNode.data=o;
+		    node.next=addNode;
+        }
+	}
+	public void add(int index , Object o){
+		int size=size();
+		if(index<0&&index>size){
+		    throw new IndexOutOfBoundsException();
+        }
+        if(index==size){
+		   add(o);
+		   return;
+        }
+        if (size==0){
+            head=new Node();
+            head.data=o;
+            return;
+        }
+        Node node=head;
+        Node addNode=new Node();
+        addNode.data=o;
+        for (int i=0;i<index-1;i++){
+            node=node.next;
+        }
+        addNode.next=node.next;
+        node.next=addNode;
+	}
+	public Object get(int index){
+        if(index<0&&index>size()-1){
+            throw new IndexOutOfBoundsException();
+        }
+        Node node=head;
+        for (int i=0;i<index;i++){
+            node=node.next;
+        }
+		return node.data;
+	}
+	public Object remove(int index){
+        if(index<0&&index>size()-1){
+            throw new IndexOutOfBoundsException();
+        }
+        Node removeNode=head;
+        if (index==0){
+            head=head.next;
+        }else {
+            Node node=head;
+            for (int i=0;i<index-1;i++){
+                node=node.next;
+            }
+            removeNode=node.next;
+            node.next=removeNode.next;
+        }
+		return removeNode.data;
+	}
+	
+	public int size(){
+	    int size=0;
+	    if(null==head){
+	        return  0;
+        }else{
+	        Node node=head.next;
+	        size=1;
+	        while (null!=node){
+	            node=node.next;
+	            size++;
+            }
+        }
+        return size;
+	}
+	
+	public void addFirst(Object o){
+		if(null==head){
+		    add(o);
+        }else {
+		   Node node =new Node();
+		   node.data=o;
+		   node.next=head;
+		   head=node;
+        }
+	}
+	public void addLast(Object o){
+		if(null==head){
+		    add(o);
+
+        }else{
+		    Node node=head;
+		    while (null!=node.next){
+		        node=node.next;
+            }
+            Node addNode=new Node();
+		    addNode.data=o;
+		    node.next=addNode;
+        }
+	}
+	public Object removeFirst(){
+		if(null==head){
+		    throw new NoSuchElementException();
+        }
+        Node node=head;
+		head=node.next;
+	    return node;
+	}
+	public Object removeLast(){
+        if(null==head){
+            throw new NoSuchElementException();
+        }
+        Node node=head;
+        if(null==node.next){
+            head=null;
+            return  node;
+        }else {
+            while (null!=node.next.next){
+                node=node.next;
+            }
+            Node lastnode=node.next;
+            node.next=null;
+            return lastnode;
+        }
+
+	}
+	public Iterator iterator(){
+	    return new Iterator() {
+	        private int currentPos=0;
+            @Override
+            public boolean hasNext() {
+               if(size()==0){
+                   return false;
+               }else {
+                   if(currentPos<size()){
+                       return  true;
+                   }else{
+                       return false;
+                   }
+               }
+
+            }
+
+            @Override
+            public Object next() {
+                Object object=get(currentPos);
+                currentPos++;
+                return object;
+            }
+        };
+
+	}
+	
+	
+	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(){
+		
+	}
+	
+	/**
+	 * 从第i个元素开始， 删除length 个元素 ， 注意i从0开始
+	 * @param i
+	 * @param length
+	 */
+	public  void remove(int i, int length){
+		
+	}
+	/**
+	 * 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
+	 * 例如当前链表 = 11->101->201->301->401->501->601->701
+	 * listB = 1->3->4->6
+	 * 返回的结果应该是[101,301,401,601]  
+	 * @param list
+	 */
+	public static int[] getElements(LinkedList list){
+		return null;
+	}
+	
+	/**
+	 * 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。
+	 * 从当前链表中中删除在list中出现的元素 
+
+	 * @param list
+	 */
+	
+	public  void subtract(LinkedList list){
+		
+	}
+	
+	/**
+	 * 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(){
+		
+	}
+	
+	/**
+	 * 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）
+	 * @param min
+	 * @param max
+	 */
+	public  void removeRange(int min, int max){
+		
+	}
+	
+	/**
+	 * 假设当前链表和参数list指定的链表均以元素依值递增有序排列（同一表中的元素值各不相同）
+	 * 现要求生成新链表C，其元素为当前链表和list中元素的交集，且表C中的元素有依值递增有序排列
+	 * @param list
+	 */
+	public  LinkedList intersection( LinkedList list){
+		return null;
+	}
+}
diff --git a/group27/514302761/src/com/company/List.java b/group27/514302761/src/com/company/List.java
new file mode 100644
index 0000000000..9e9f7bacb7
--- /dev/null
+++ b/group27/514302761/src/com/company/List.java
@@ -0,0 +1,9 @@
+package com.company;
+
+public interface List {
+	public void add(Object o);
+	public void add(int index, Object o);
+	public Object get(int index);
+	public Object remove(int index);
+	public int size();
+}
diff --git a/group27/514302761/src/com/company/Queue.java b/group27/514302761/src/com/company/Queue.java
new file mode 100644
index 0000000000..3cd4984585
--- /dev/null
+++ b/group27/514302761/src/com/company/Queue.java
@@ -0,0 +1,21 @@
+package com.company;
+
+public class Queue {
+	private LinkedList elementDatas=new LinkedList();
+	public void enQueue(Object o){
+        elementDatas.add(o);
+	}
+	
+	public Object deQueue(){
+
+	    return elementDatas.removeFirst();
+	}
+	
+	public boolean isEmpty(){
+		return size()==0;
+	}
+	
+	public int size(){
+		return elementDatas.size();
+	}
+}
diff --git a/group27/514302761/src/com/company/Stack.java b/group27/514302761/src/com/company/Stack.java
new file mode 100644
index 0000000000..c0220f3a66
--- /dev/null
+++ b/group27/514302761/src/com/company/Stack.java
@@ -0,0 +1,32 @@
+package com.company;
+
+import java.util.EmptyStackException;
+
+public class Stack {
+	private ArrayList elementData = new ArrayList();
+	
+	public void push(Object o){
+		elementData.add(o);
+	}
+	
+	public Object pop()
+	{
+	 if(isEmpty()){
+	 	throw new EmptyStackException();
+	 }
+	 return elementData.get(size()-1);
+	}
+	
+	public Object peek(){
+		if(isEmpty()){
+			throw new EmptyStackException();
+		}
+		return elementData.get(size()-1);
+	}
+	public boolean isEmpty(){
+		return size()==0;
+	}
+	public int size(){
+		return elementData.size();
+	}
+}