Merge pull request #33 from yuyaoche/master

第一周作业提交

group24/635501270/week1/collections/ArrayList.java

@@ -0,0 +1,96 @@
+package week1.collections;
+
+import java.util.Arrays;
+
+public class ArrayList implements List {
+	private int size = 0;	//声明数组长度
+
+	private Object[] elementData = new Object[0];	//声明一个Object数组，初始大小为10
+
+	/**
+	 * 将元素添加到末尾
+	 */
+	public boolean add(Object o){
+		ensureCapacity(size+1);
+		elementData[size] = o;
+		size++;
+		return true;
+	}
+
+	/**
+	 * 将元素插入到index位置
+	 */
+	public void add(int index, Object o){
+		exception(index);
+		ensureCapacity(size+1);
+		System.arraycopy(elementData, index, elementData, index+1, size-index);
+		elementData[index] = o;
+		size++;
+	}
+
+	/**
+	 * 获得index位置的元素
+	 */
+	public Object get(int index){
+		exception(index);
+		return elementData[index];
+	}
+
+	/**
+	 * 删除index位置的元素并返回
+	 */
+	public Object remove(int index){
+		exception(index);
+		Object o = elementData[index];
+		System.arraycopy(elementData, index+1, elementData, index, size-index-1);
+		size--;
+		return o;
+	}
+
+	private void exception(int index) {
+		if(index > size || index < 0){
+			throw new ArrayIndexOutOfBoundsException("index"+index+"越界");
+		}
+	}
+
+	/**
+	 * 获取元素个数
+	 */
+	public int size(){
+		return size;
+	}
+
+	/**
+	 * 获取迭代器
+	 * @return
+	 */
+	public Iterator iterator(){
+		return new ArrayListIterator();
+	}
+
+	private class ArrayListIterator implements Iterator{
+		int pos = 0;
+		@Override
+		public boolean hasNext() {
+			return pos<size();
+		}
+
+		@Override
+		public Object next() {
+			int newPos = pos;
+			pos++;
+			return elementData[newPos];
+		}
+	}
+
+	/**
+	 * 自动扩容
+	 * @param minCapacity
+	 */
+	public void ensureCapacity(int minCapacity){
+		if(minCapacity > elementData.length){
+			int newCapacity = Math.max(minCapacity, elementData.length*2);
+			elementData = Arrays.copyOf(elementData, newCapacity);
+		}
+	}
+}

group24/635501270/week1/collections/BinaryTreeNode.java

@@ -0,0 +1,57 @@
+package week1.collections;
+
+public class BinaryTreeNode {
+
+	private Object data;
+	private BinaryTreeNode left;
+	private BinaryTreeNode right;
+
+	public Object getData() {
+		return data;
+	}
+	public void setData(Object data) {
+		this.data = 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(Object o){
+		if(data == null){
+			data = o;
+			return this;
+		}
+		if(o instanceof Integer || this.data instanceof Integer){
+			int compare = (Integer)this.data - (Integer)o;
+			if(compare > 0){
+				if(this.left == null){
+					this.left = new BinaryTreeNode();
+					this.left.data = o;
+					return this.left;
+				}else{
+					return this.left.insert(o);
+				}
+			}else if(compare < 0){
+				if(this.right == null){
+					this.right = new BinaryTreeNode();
+					this.right.data = o;
+					return this.right;
+				}else{
+					return this.right.insert(o);
+				}
+			}else{
+				return this;
+			}
+		}
+		return  null;
+	}
+}

group24/635501270/week1/collections/Iterator.java

@@ -0,0 +1,6 @@
+package week1.collections;
+
+public interface Iterator {
+	public boolean hasNext();
+	public Object next();
+}

group24/635501270/week1/collections/LinkedList.java

@@ -0,0 +1,204 @@
+package week1.collections;
+
+public class LinkedList implements List {
+	private int size = 0;
+	private Node head;
+	private Node last;
+
+	public boolean add(Object o){
+		Node newNode = new Node(o);
+		if(head == null){
+			last = newNode;
+			head = newNode;
+		}else{
+			Node oldLast = last;
+			last = newNode;
+			oldLast.next = last;
+		}
+		size++;
+		return true;
+	}
+	public void add(int index , Object o){
+		outOfIndex(index);
+		if(index == 0){
+			Node oldHead = head;
+			head = new Node(o);
+			head.next = oldHead;
+		}else{
+			Node h = getNode(index-1);
+			Node newNode = new Node(o);
+			newNode.next = h.next;
+			h.next = newNode;
+		}
+		size++;
+	}
+	public Object get(int index){
+		Node h = getNode(index);
+		return h.data;
+	}
+	private Node getNode(int index) {
+		outOfIndex(index);
+		Node h = head;
+		for(int i=0;i<index;i++){
+			h = h.next;
+		}
+		return h;
+	}
+	private void outOfIndex(int index) {
+		if(index >= size || index < 0){
+			throw new IndexOutOfBoundsException("Index"+index+"越界");
+		}
+	}
+	public Object remove(int index){
+		outOfIndex(index);
+		Object data;
+		if(index==0){
+			Node oldHead = head;
+			head = head.next;
+			data = oldHead.data;
+			oldHead = null;
+		}else{
+			Node preNode = getNode(index-1);
+			if(preNode.next==last){
+				Node oldLast = last;
+				last = preNode;
+				data = oldLast.data;
+				oldLast = null;
+			}else{
+				Node removeNode = preNode.next;
+				preNode.next = preNode.next.next;
+				data = removeNode.data;
+				removeNode = null;
+			}
+		}
+		size--;
+		return data;
+	}
+
+	public int size(){
+		return size;
+	}
+
+	public void addFirst(Object o){
+		add(0,o);
+	}
+	public void addLast(Object o){
+		if(last==null){
+			add(o);
+		}else{
+			Node oldLast = last;
+			last = new Node(o);
+			oldLast.next = last;
+		}
+		size++;
+	}
+	public Object removeFirst(){
+		return remove(0);
+	}
+	public Object removeLast(){
+		return remove(size-1);
+	}
+	public Iterator iterator(){
+		return new LinkedListIterator();
+	}
+	private class LinkedListIterator implements Iterator{
+		int pos = 0;
+		@Override
+		public boolean hasNext() {
+			return pos<size();
+		}
+
+		@Override
+		public Object next() {
+			return get(pos++);
+		}
+	}
+
+	private static  class Node{
+		Object data;
+		Node next;
+		public Node(){
+
+		}
+		public Node(Object o){
+			this.data = o;
+			this.next = null;
+		}
+	}
+
+	/**
+	 * 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listB均包含已升序排列的整数
+	 * 从当前链表中取出那些listB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  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listB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;
+	}
+}

group24/635501270/week1/collections/List.java

@@ -0,0 +1,9 @@
+package week1.collections;
+
+public interface List {
+	public boolean add(Object o);
+	public void add(int index, Object o);
+	public Object get(int index);
+	public Object remove(int index);
+	public int size();
+}