第一周作业-白杨

group27/772642286/basic/ArrayList.java

@@ -0,0 +1,80 @@
+package week01.basic;
+
+import java.util.Arrays;
+
+public class ArrayList implements List {
+
+	private int size = 0;
+
+	private Object[] elementData = new Object[100];
+
+	public void add(Object o){
+		add(size , o);
+	}
+	public void add(int index, Object o){
+		if(index<0||index > size){
+			throw new ArrayIndexOutOfBoundsException(index);
+		}
+		size++;
+		if(size>=elementData.length){
+			expand();
+		}
+		for(int i = size -1 ;i> index; i--){
+			elementData[i] = elementData[i-1];
+		}
+		elementData[index] = o;
+	}
+
+	public Object get(int index){
+		if(index<0||index>=size){
+			throw new ArrayIndexOutOfBoundsException(index);
+		}
+		return elementData[index];
+	}
+
+	public Object remove(int index){
+		if(index<0||index>=size){
+			throw new ArrayIndexOutOfBoundsException(index);
+		}
+		Object o = elementData[index];
+		for(int i = index ;i< size - 1; i++){
+			elementData[i] = elementData[i+1];
+		}
+		elementData[size - 1] = null;
+		size--;
+		return o;
+	}
+
+	public int size(){
+		return size;
+	}
+
+	public Iterator iterator(){
+		return new ArrayListIterator();
+	}
+
+	class ArrayListIterator implements Iterator{
+
+		int count = 0;
+		@Override
+		public boolean hasNext() {
+			count++;
+			if(size<= count){
+				return false; 
+			}
+			return true;
+		}
+
+		@Override
+		public Object next() {
+			return elementData[count];
+		}
+
+	}
+
+
+	private void expand(){
+		elementData = Arrays.copyOf(elementData, elementData.length*2);
+	}
+
+}

group27/772642286/basic/BinaryTreeNode.java

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+package week01.basic;
+
+public class BinaryTreeNode<T extends Comparable> {
+
+	private T data;
+	private BinaryTreeNode left;
+	private BinaryTreeNode right;
+
+	public Object getData() {
+		return data;
+	}
+	public void setData(T 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(T o){
+		return insert(this,o);
+	}
+
+
+	public BinaryTreeNode insert(BinaryTreeNode root,T o){
+		if(o.compareTo(root) >= 0){
+			if(root.left == null){
+				BinaryTreeNode binaryTreeNode = new BinaryTreeNode();
+				root.left = binaryTreeNode;
+				binaryTreeNode.data = o;
+				return binaryTreeNode;
+			}
+			return insert(root.left, o);
+		}
+		else{
+			if (root.right == null) {
+				BinaryTreeNode binaryTreeNode = new BinaryTreeNode();
+				root.right = binaryTreeNode;
+				binaryTreeNode.data = o;
+				return binaryTreeNode;
+			}
+			return insert(root.right, o);
+		}
+	}
+
+
+}

group27/772642286/basic/Iterator.java

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+package week01.basic;
+
+public interface Iterator {
+	public boolean hasNext();
+	public Object next();
+
+}

group27/772642286/basic/LinkedList.java

@@ -0,0 +1,208 @@
+package week01.basic;
+
+import java.util.Objects;
+
+public class LinkedList implements List {
+
+	private Node head;
+
+	private Node tail;
+
+	private int size;
+
+	public void add(Object o){
+		Node node = new Node();
+		node.data = o;
+		if(Objects.isNull(head)){
+			head = node;
+			tail = head;
+			size++;
+			return ;
+		}
+		tail.next = node;
+		tail = node;
+		size++;
+	}
+
+	public void add(int index , Object o){
+		if(index<0 || index >size){
+			throw new ArrayIndexOutOfBoundsException(index);
+		}		
+		if(Objects.isNull(head)||index==size){
+			add(o);
+			return;
+		}
+
+		Node headNode = getNode(index - 1);
+		Node temp = headNode.next;
+		Node node = new Node();
+		node.data = o;
+		node.next = temp;
+		headNode.next = node;
+		size++;
+	}
+
+
+	public Object get(int index){
+		if(index< 0 || index >= size){
+			throw new ArrayIndexOutOfBoundsException(index);
+		}
+
+		return getNode(index).data;
+	}
+
+	private Node getNode(int index){
+
+
+		int count = 0;
+		Node headNode = head;
+		while(count< index){
+			headNode = headNode.next;
+			count++;
+		}
+		return headNode;
+	}
+
+	public Object remove(int index){
+		if(index< 0 || index >= size){
+			throw new ArrayIndexOutOfBoundsException(index);
+		}
+
+		if(index==0){
+			Node node = head;
+			head = head.next;
+			size --;
+			return node.data;
+		}
+
+		Node headNode = getNode(index - 1);
+		Node node = headNode.next;
+		head.next = node.next;
+		size --;
+		return node.data;
+	}
+
+	public int size(){
+		return size;
+	}
+
+	public void addFirst(Object o){
+		add(0, o);
+	}
+	public void addLast(Object o){
+		add(size,o);
+	}
+	public Object removeFirst(){
+		return remove(0);
+	}
+	public Object removeLast(){
+		return remove(size);
+	}
+	public Iterator iterator(){
+		return new LinkedListIterator();
+	}
+
+	class LinkedListIterator implements Iterator{
+
+		private Node currentNode;
+
+		@Override
+		public boolean hasNext() {
+			if(currentNode==null){
+				 currentNode = head;
+			}else{
+			     currentNode = currentNode.next;
+			}
+			return Objects.nonNull(currentNode);
+		}
+
+		@Override
+		public Object next() {
+			return currentNode.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(){
+
+	}
+
+	/**
+	 * 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;
+	}
+}

group27/772642286/basic/List.java

@@ -0,0 +1,9 @@
+package week01.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();
+}

group27/772642286/basic/Queue.java

@@ -0,0 +1,21 @@
+package week01.basic;
+
+public class Queue {
+	private LinkedList elementData = new LinkedList();
+
+	public void enQueue(Object o){	
+		elementData.add(o);
+	}
+
+	public Object deQueue(){
+		return elementData.remove(elementData.size());
+	}
+
+	public boolean isEmpty(){
+		return elementData.size() == 0;
+	}
+
+	public int size(){
+		return elementData.size();
+	}
+}