去掉非本周的作业

group24/626451284Learning/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.github.wdn</groupId>
+    <artifactId>coding2017</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+
+</project>

group24/626451284Learning/src/main/java/com/github/wdn/coding2017/basic/ArrayList.java

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+package com.github.wdn.coding2017.basic;
+
+import java.util.Arrays;
+
+public class ArrayList implements List {
+
+	private int size = 0;
+
+	private Object[] elementData;
+	public ArrayList(){
+		elementData = new Object[10];
+	}
+	public ArrayList(int size){
+		elementData = new Object[size];
+	}
+	public void add(Object o){
+		if(size>=elementData.length){
+			elementData = Arrays.copyOf(elementData,elementData.length*2);
+		}
+		elementData[size]=o;
+		size++;
+	}
+	public void add(int index, Object o){
+		Object[] newElementData;
+		if(size()+1>=elementData.length){
+			newElementData=new Object[elementData.length*2];
+
+		}else{
+			newElementData=new Object[elementData.length];
+		}
+		for (int i = 0; i < elementData.length; i++) {
+			if(index==1){
+				newElementData[i]=o;
+			}else if(i>index) {
+				newElementData[i]=elementData[i-1];
+			}else{
+				newElementData[i]=elementData[i];
+			}
+		}
+		elementData = newElementData;
+		size++;
+	}
+
+	public Object get(int index){
+		if(index>=size){
+			throw new IndexOutOfBoundsException();
+		}
+		return elementData[index];
+	}
+
+	public Object remove(int index) {
+		if(index>=size){
+			throw new IndexOutOfBoundsException();
+		}
+		Object returnO = elementData[index];
+		for (int i = index; i < size; i++) {
+			if(i==size-1){
+				elementData[i]=null;
+			}else {
+				elementData[i] = elementData[i + 1];
+			}
+		}
+		size--;
+		return returnO;
+	}
+
+	public int size(){
+		return size;
+	}
+
+	public Iterator iterator(){
+		return null;
+	}
+
+	public static void main(String[] args) {
+		ArrayList list = new ArrayList(2);
+		list.add("1");
+		list.add("2");
+		list.remove(1);
+		list.add("3");
+		for (int i = 0; i < list.size(); i++) {
+			System.out.println(list.get(i));
+		}
+		int[] i = {};
+		System.out.println(i[0]);
+	}
+
+}

group24/626451284Learning/src/main/java/com/github/wdn/coding2017/basic/BinaryTreeNode.java

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+package com.github.wdn.coding2017.basic;
+
+/**
+ * TODO 代码在公司电脑里。。。后续提交
+ */
+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){
+		return  null;
+	}
+
+}

group24/626451284Learning/src/main/java/com/github/wdn/coding2017/basic/Iterator.java

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+package com.github.wdn.coding2017.basic;
+
+/**
+ * TODO 主要考虑遍历中安全删除元素的实现
+ */
+public interface Iterator {
+	public boolean hasNext();
+	public Object next();
+
+}

group24/626451284Learning/src/main/java/com/github/wdn/coding2017/basic/LinkedList.java

@@ -0,0 +1,233 @@
+package com.github.wdn.coding2017.basic;
+
+/**
+ * TODO 只是简单实现 缺少对边界的处理
+ * 参考JDK源码改为更优雅的实现
+ */
+
+public class LinkedList implements List {
+
+	private Node head;
+	private Node tail;
+	private int size;
+
+	public LinkedList(){
+		this.head=null;
+		this.tail=null;
+	}
+	public void add(Object o){
+		Node newNode = new Node(o);
+		if (head == null) {
+			head = newNode;
+			tail = newNode;
+		}else{
+			tail.setNext(newNode);
+			newNode.setPre(tail);
+			tail = newNode;
+		}
+		size++;
+	}
+	public void add(int index , Object o){
+		checkIndex(index);
+		Node indexNode = getNode(index);
+		Node newNode = new Node(o);
+		Node pre = indexNode.getPre();
+		if(pre!=null){
+			pre.setNext(newNode);
+		}else{
+			head = newNode;
+		}
+		newNode.setPre(pre);
+		newNode.setNext(indexNode);
+		indexNode.setPre(newNode);
+	}
+	private void checkIndex(int index){
+		if(index >= size || index <0){
+			throw new IndexOutOfBoundsException();
+		}
+	}
+	private Node getNode(int index){
+		checkIndex(index);
+		// TODO这里可以优化，先判断index在前半部还是后半部分 然后确定从头部或者尾部查找
+		Node result=null;
+		if(index==0){
+			return head;
+		}
+		if(index==size-1){
+			return tail;
+		}
+		for (int i = 0; i < index; i++) {
+			result = head.getNext();
+		}
+		return result;
+	}
+	public Object get(int index){
+		return getNode(index).getData();
+	}
+	public Object remove(int index){
+		checkIndex(index);
+		Node indexNode = getNode(index);
+		Node pre = indexNode.getPre();
+		Node next = indexNode.getNext();
+		if(pre!=null){
+			pre.setNext(next);
+		}else{
+			head = next;
+		}
+		if(next!=null){
+			next.setPre(pre);
+		}else{
+			tail = pre;
+		}
+		return indexNode.getData();
+	}
+
+	public int size(){
+		return size;
+	}
+
+	public void addFirst(Object o){
+		Node newNode = new Node(o);
+		head.setPre(newNode);
+		newNode.setNext(head);
+		head = newNode;
+	}
+	public void addLast(Object o){
+		Node newNode = new Node(o);
+		tail.setNext(newNode);
+		newNode.setPre(tail);
+		tail = newNode;
+	}
+	public Object removeFirst(){
+		Node next = head.getNext();
+		Node oldHead = head;
+		head = next;
+		head.setPre(null);
+		return oldHead;
+	}
+	public Object removeLast(){
+		Node oldTail = tail;
+		Node pre = tail.getPre();
+		tail = pre;
+		tail.setNext(null);
+		return oldTail;
+	}
+	public Iterator iterator(){
+
+		return null;
+	}
+
+	/**
+	 * JDK 中使用构造方法的方式设置next和pre减少不必要的getset方法更优雅
+	 */
+	private static  class Node{
+
+		Object data;
+		Node next;
+		Node pre;
+		public Node(){
+
+		}
+		public Node(Object data){
+			this.data = data;
+		}
+		public Object getData() {
+			return data;
+		}
+
+		public void setData(Object data) {
+			this.data = data;
+		}
+
+		public Node getNext() {
+			return next;
+		}
+
+		public void setNext(Node next) {
+			this.next = next;
+		}
+
+		public Node getPre() {
+			return pre;
+		}
+
+		public void setPre(Node pre) {
+			this.pre = pre;
+		}
+	}
+
+	/**
+	 * 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;
+	}
+}

group24/626451284Learning/src/main/java/com/github/wdn/coding2017/basic/List.java

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+package com.github.wdn.coding2017.basic;
+
+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();
+}