Merge pull request #32 from xxxxxxttt817/master

The first week home work
zhanglifeng · Feb 27, 2017 · 7dbfe04 · 7dbfe04
2 parents 362219f + 1d6d299
commit 7dbfe04
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diff --git a/group01/553624797/code2017/src/com/xxt/DataStructure/List.java b/group01/553624797/code2017/src/com/xxt/DataStructure/List.java
@@ -0,0 +1,9 @@
+package com.xxt.DataStructure;
+
+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/group01/553624797/code2017/src/com/xxt/DataStructure/MyArrayList.java b/group01/553624797/code2017/src/com/xxt/DataStructure/MyArrayList.java
@@ -0,0 +1,99 @@
+package com.xxt.DataStructure;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+
+/**
+ * Created by star on 2017/2/26.
+ */
+public class MyArrayList implements List {
+
+
+
+    private Object[] elementData;
+    private int size = elementData.length;
+
+
+    public MyArrayList(int initialCapacity) {
+        if (initialCapacity > 0) {
+            this.elementData = new Object[initialCapacity];
+        } else {
+            throw new IllegalArgumentException("Illegal Capacity: " + initialCapacity);
+        }
+    }
+
+    public MyArrayList() {
+        this(10);
+    }
+
+
+    @Override
+    public void add(Object o) {
+        ensureCapacity(size + 1);
+        elementData[size + 1] = o;
+    }
+
+    @Override
+    public void add(int index, Object o) {
+        //判断数组下标是否越界
+        if(index < 0 || index > elementData.length){
+            throw new IndexOutOfBoundsException("index : "+index+"size : "+size);
+        }
+        ensureCapacity(index);
+        System.arraycopy(elementData, index,elementData, index + 1, size - index);
+        elementData[index] = o;
+        size++;
+    }
+
+    @Override
+    public Object get(int index) {
+        return elementData[index];
+    }
+
+    @Override
+    public Object remove(int index) {
+        //判断数组下标是否越界
+        if(index < 0 || index > elementData.length){
+            throw new IndexOutOfBoundsException("index : "+index+"size : "+size);
+        }
+
+
+        //取出删除的值
+        Object oldValue = elementData[index];
+
+        //做删除操作同样是复制数组
+        //计算要删除的数量
+        int numMoved = size - index - 1;
+        if ( numMoved > 0){
+            System.arraycopy(elementData, index + 1, elementData, index, numMoved);
+        }
+
+        //将数组最后一个元素置为空，让GC回收
+        elementData[size - 1] = null;
+        return oldValue;
+
+    }
+
+    @Override
+    public int size() {
+        return elementData.length;
+    }
+
+
+    //判断是否扩容
+    public void ensureCapacity(int minCapacity) {
+        //取得当前数组容量
+        int currentCapacity = elementData.length;
+        //如果最小需要的容量小于当前数组容量则需要扩容
+        if (minCapacity < currentCapacity) {
+            int newCapacity = currentCapacity + (currentCapacity >> 1);
+            //如果扩容后的长度还是小于最小需要的长度，则直接以最小需要的长度作为当前数组的长度
+            if (newCapacity < minCapacity) {
+                newCapacity = minCapacity;
+                elementData = Arrays.copyOf(elementData, newCapacity);
+            }
+        }
+
+    }
+
+}
diff --git a/group01/553624797/code2017/src/com/xxt/DataStructure/MyLinkedList.java b/group01/553624797/code2017/src/com/xxt/DataStructure/MyLinkedList.java
@@ -0,0 +1,141 @@
+package com.xxt.DataStructure;
+
+import java.util.Iterator;
+
+import java.util.LinkedList;
+import java.util.function.Consumer;
+
+/**
+ * Created by star on 2017/2/25.
+ */
+public class MyLinkedList<E> implements List{
+
+    public  static class Node<E>{
+        E elementData;
+        Node<E> prerious;
+        Node<E> next;
+
+        public Node(Node<E> prerious , E elementData, Node<E> next) {
+            this.prerious = prerious;
+            this.elementData= elementData;
+            this.next = next;
+        }
+    }
+
+
+
+    private Node header;
+    private Node last;
+
+    private int size = 0;
+
+
+    //往最后一个节点添加元素
+    @Override
+    public void add(Object elementData) {
+        addBefore((E) elementData, last);
+    }
+
+    @Override
+    public void add(int index, Object elementData) {
+        addBefore((E) elementData, (index == size ? last : node(index)));
+    }
+
+    @Override
+    public Object get(int index) {
+        return node(index).elementData;
+
+    }
+
+    //获取index位置的节点
+    private Node<E> node(int index){
+        if(index < 0 || index > size){
+            throw  new IndexOutOfBoundsException("数组下标越界"+size);
+        }
+
+        if(index < (size >> 1)){
+            Node<E> e = header;
+            for(int i = 0; i < index; i ++){
+                e = header.next;
+                return e;
+            }
+        }else {
+            Node<E> e = last;
+            for(int i = size - 1; i > index; i--){
+                e = last.prerious;
+                return e;
+            }
+        }
+        return null;
+    }
+
+
+    @Override
+    public Object remove(int index) {
+
+        if (index < 0 || index > size) {
+            throw new IndexOutOfBoundsException("inde :" + index);
+        }
+
+        return remove(node(index));
+    }
+
+
+
+    //返回被删除的节点
+    private Object remove(Node<E> e){
+       E movedElementData = e.elementData;
+
+        //被删除节点的上个节点指向该节点的下个节点
+       e.prerious.next = e.next;
+
+        //被删除节点的下个节点指向该节点的上个节点
+        e.next.prerious = e.prerious;
+
+
+        //将该节点置为空，让GC能够回收
+        e.next = e.prerious = null;
+        e.elementData = null;
+        //长度-1
+        size--;
+        return movedElementData;
+    }
+
+
+    @Override
+    public int size() {
+        return size;
+    }
+
+    public Object removeFirst(){
+        return remove(header.next);
+
+
+    }
+
+    public Object removeLast(){
+        return remove(last.prerious);
+    }
+
+    public Iterator iterator(){
+        return null;
+    }
+
+
+
+    //插入一个新的节点
+    private Node<E> addBefore(E e, Node<E> node){
+
+        Node<E> newNode = new Node<E>(node.prerious, e, node.next);
+
+        //将上个节点的next指向自己
+        newNode.prerious.next = newNode;
+
+        //将下个节点的previous指向自己
+        newNode.next.prerious = newNode;
+
+        size++;
+        return newNode;
+    }
+
+}
diff --git a/group01/553624797/code2017/src/com/xxt/DataStructure/MyQueue.java b/group01/553624797/code2017/src/com/xxt/DataStructure/MyQueue.java
@@ -0,0 +1,88 @@
+package com.xxt.DataStructure;
+
+import java.util.Iterator;
+
+/**
+ * Created by star on 2017/2/26.
+ */
+public class MyQueue{
+
+
+    public  static class Node<E>{
+        Object elementData;
+        Node<E> prerious;
+        Node<E> next;
+
+        public Node(Object elementData, Node<E> prerious, Node<E> next) {
+            this.elementData = elementData;
+            this.prerious = prerious;
+            this.next = next;
+        }
+
+    }
+
+
+    private MyQueue.Node header;
+    private MyQueue.Node last;
+
+    private int size = 0;
+
+
+    //入队操作.在链表的头节点插入元素
+    public void enQueue(Object o){
+        addBefore(o, header);
+    }
+
+
+    //出队操作，返回链表的尾节点的元素
+    public Object deQueue(){
+        return node(size);
+    }
+
+
+    public boolean isEmpty(){
+        return header == last;
+    }
+
+
+
+    public int size(){
+        return size;
+    }
+
+   private Node addBefore(Object o , Node node){
+       Node newNode = new Node(o, node.prerious, node.next);
+
+       newNode.prerious.next = newNode;
+       newNode.next.prerious = newNode;
+
+       size++;
+       return newNode;
+
+   }
+
+
+    private Node node(int index){
+        if(index < 0 || index > size){
+            throw  new IndexOutOfBoundsException("数组下标越界"+size);
+        }
+
+        if(index < (size >> 1)){
+            Node e = header;
+            for(int i = 0; i < index; i ++){
+                e = header.next;
+                return e;
+            }
+        }else {
+            Node e = last;
+            for(int i = size - 1; i > index; i--){
+                e = last.prerious;
+                return e;
+            }
+        }
+        return null;
+    }
+
+
+
+}
diff --git a/group01/553624797/code2017/src/com/xxt/DataStructure/MyStack.java b/group01/553624797/code2017/src/com/xxt/DataStructure/MyStack.java
@@ -0,0 +1,52 @@
+package com.xxt.DataStructure;
+
+import java.util.EmptyStackException;
+
+/**
+ * Created by star on 2017/2/26.
+ */
+public class MyStack {
+
+
+    //采用数组实现；
+    private Object[] array;
+    //栈顶指针
+    private int top;
+    private final static int size = 100;
+
+    public MyStack(Object[] array, int top) {
+        this.array = array;
+        //空栈
+        top = -1 ;
+    }
+
+    public void push(Object elementData){
+        //栈满
+        if(top == size - 1){
+            throw new StackOverflowError();
+        }else {
+            array[++top] = elementData;
+        }
+    }
+
+    //弹栈
+    public Object pop(){
+        if( top == -1){
+            throw  new EmptyStackException();
+        }else {
+            return array[top--];
+        }
+    }
+
+    public boolean isEmpty(){
+        return top == -1;
+    }
+
+    public  Object peek(){
+        if(top == -1){
+            throw new EmptyStackException();
+        }else {
+            return array[top];
+        }
+    }
+}