第一周作业

rockyyu66 · rockyyu66 · commit 6f1182021f6a · 2017-02-26T21:18:07.000+08:00
diff --git a/group01/275150374/275150374Learning/src/task01/ArrayList.java b/group01/275150374/275150374Learning/src/task01/ArrayList.java
@@ -1,8 +1,86 @@
 package task01;
 
+import java.util.Arrays;
+
 /**第一周作业
- * 自己实现一个
+ * 自己实现一个 ArrayList
  * Created by eurry on 2017/2/26.
  */
 public class ArrayList {
+    /**
+     * ArrayList的长度
+     */
+    private int size = 0;
+
+    private Object[] elementData = {};
+
+    public void add(Object o){
+        elementData = Arrays.copyOf(elementData, size+1);
+        elementData[size] = o;
+        size++;
+    }
+
+    public void add(int index, Object o){
+        if(index < size){
+            elementData = Arrays.copyOf(elementData, size+1);
+            System.arraycopy(elementData, index, elementData, index+1, size-index);
+            elementData[index] = o;
+            size++;
+        }else{
+            elementData = Arrays.copyOf(elementData, index+1);
+            elementData[index] = o;
+            size = index+1;
+        }
+    }
+
+    public Object get(int index){
+        if(index < size){
+            return elementData[index];
+        }else{
+            throw new IndexOutOfBoundsException("导致对数组范围以外的数据的访问");
+        }
+    }
+
+    public Object remove(int index){
+        if(index < size){
+            Object re = elementData[index];
+            System.arraycopy(elementData, index+1, elementData, index, size-index-1);
+            elementData = Arrays.copyOf(elementData, size-1);
+            size--;
+            return re;
+        }else{
+            throw new IndexOutOfBoundsException("导致对数组范围以外的数据的访问");
+        }
+    }
+
+    public int size(){
+        return size;
+    }
+
+    public String toString(){
+        String str = null;
+        if(elementData.length > 0){
+            str = "";
+            for (Object anElementData : elementData) {
+                str += anElementData.toString() + ",";
+            }
+            str = str.substring(0, str.length()-1);
+        }
+        return str;
+    }
+
+    /**
+     * 测试
+     */
+    public static void main(String[] str){
+        ArrayList list = new ArrayList();
+        list.add("A");
+        list.add("B");
+        list.add(1, "C");
+        list.add("D");
+        Object d = list.get(3);
+        Object dd = list.remove(3);
+        System.out.println(list.size());
+        System.out.println(list.toString());
+    }
 }
diff --git a/group01/275150374/275150374Learning/src/task01/LinkedList.java b/group01/275150374/275150374Learning/src/task01/LinkedList.java
@@ -0,0 +1,162 @@
+package task01;
+
+import java.util.Arrays;
+
+/**第一周作业
+ * 自己实现一个 LinkedList
+ * Created by eurry on 2017/2/26.
+ */
+public class LinkedList {
+
+    private int size = 0;
+    private Node head=null;
+
+    public void add(Object o){
+        if(size == 0){
+            head = new Node(o);
+        }else{
+            Node next = head;
+            while(next.next != null){
+                next = next.next;
+            }
+            next.next = new Node(o);
+        }
+        size++;
+    }
+
+    public void add(int index, Object o){
+        if(index <= size){
+            if(size == 0){
+                add(o);
+            }else{
+                if(index==0){
+                    addFirst(o);
+                }else if(index==size){
+                    add(o);
+                }else{
+                    Node next = head;
+                    for(int i=0; i<size; i++){
+                        Node temp = next.next;
+                        if(i==index-1){
+                            next.next = new Node(o);
+                            next.next.next = temp;
+                        }
+                        next = next.next;
+                    }
+                    size++;
+                }
+            }
+        }else{
+            throw new IndexOutOfBoundsException("越界");
+        }
+    }
+
+    public void addFirst(Object o){
+        Node newHead = new Node(o);
+        newHead.next = head;
+        head = newHead;
+        size++;
+    }
+
+
+    public Object get(int index){
+        Node ele = null;
+        Node next = head;
+        for(int i=0; i<size; i++){
+            if(i == index)
+                ele = next;
+            next = next.next;
+        }
+        return ele.element;
+    }
+
+    public Object remove(int index){
+        if(index < size){
+            Node re = null;
+            if(index==0){
+                re = head;
+                head = head.next;
+            }else{
+                Node prev = null;
+                Node next = head;
+                for(int i=0; i<size; i++){
+                    if(i == index-1)
+                        prev = next;
+                    next = next.next;
+                }
+                re = prev.next;
+                prev.next = prev.next.next;
+            }
+            size--;
+            return re.element;
+        }else{
+            throw new IndexOutOfBoundsException("越界");
+        }
+    }
+
+    public Object removeFirst(){
+        Object obj = head.element;
+        head = head.next;
+        size--;
+        return obj;
+    }
+
+    public Object removeLast(){
+        Node prev = null;
+        Node next = head;
+        for(int i=0; i<size; i++){
+            if(i == size-2)
+                prev = next;
+            next = next.next;
+        }
+        Object obj = prev.next.element;
+        prev.next = null;
+        size--;
+        return obj;
+    }
+
+    public int size(){
+        return size;
+    }
+
+    public String toString(){
+        String str = "";
+        if(size > 0){
+            Node ele = null;
+            Node next = head;
+            for(int i=0; i<size; i++){
+                str += next.element.toString() + ",";
+                next = next.next;
+            }
+            str = str.substring(0, str.length()-1);
+        }
+        return str;
+    }
+
+    /**
+     * 静态内部类：节点
+     */
+    private static class Node{
+        Object element;
+        Node next = null;
+        Node(Object o){
+            this.element = o;
+        }
+    }
+
+    /**
+     * 测试
+     */
+    public static void main(String[] strs){
+        LinkedList list = new LinkedList();
+        list.add("A");
+        list.add("B");
+        list.add(1, "C");
+        list.add("D");
+        Object d = list.get(3);
+        Object dd = list.remove(3);
+        System.out.println(list.size());
+        System.out.println(list.toString());
+    }
+
+}
diff --git a/group01/275150374/275150374Learning/src/task01/Main.java b/group01/275150374/275150374Learning/src/task01/Main.java
@@ -0,0 +1,12 @@
+package task01;
+
+/**
+ * Created by eurry on 2017/2/26.
+ */
+public class Main {
+
+    public static void main(String[] strs){
+
+    }
+
+}
diff --git a/group01/275150374/275150374Learning/src/task01/Queue.java b/group01/275150374/275150374Learning/src/task01/Queue.java
@@ -0,0 +1,42 @@
+package task01;
+
+import java.util.Arrays;
+
+/**第一周作业
+ * 自己实现一个 队列
+ * Created by eurry on 2017/2/26.
+ */
+public class Queue {
+
+    private int size=0;
+    private Object[] elementData = {};
+
+    /**
+     * 入队列
+     */
+    public void enQueue(Object o){
+        elementData = Arrays.copyOf(elementData, size+1);
+        elementData[size] = o;
+        size++;
+    }
+
+    /**
+     * 出队列
+     */
+    public Object deQueue(){
+        Object result = elementData[0];
+        Object[] newData = new Object[size-1];
+        System.arraycopy(elementData, 1, newData, 0,size-1);
+        elementData = newData;
+        size--;
+        return result;
+    }
+
+    public boolean isEmpty(){
+        return size==0;
+    }
+
+    public int size(){
+        return size;
+    }
+}
diff --git a/group01/275150374/275150374Learning/src/task01/Stack.java b/group01/275150374/275150374Learning/src/task01/Stack.java
@@ -0,0 +1,30 @@
+package task01;
+
+/**第一周作业
+ * 自己实现一个 栈
+ * Created by eurry on 2017/2/26.
+ */
+public class Stack {
+
+    private ArrayList elementData= new ArrayList();
+
+    public void push(Object o){
+        elementData.add(o);
+    }
+
+    public Object pop(){
+        return elementData.remove(elementData.size()-1);
+    }
+
+    /**
+     *查看栈顶对象而不移除它
+     */
+    public Object peek(){
+        return elementData.get(elementData.size()-1);
+    }
+
+    public boolean isEmpty(){
+        return elementData.size()==0;
+    }
+}
+
