Merge pull request #8 from silencehe09/master

基础集合类实现
diliuzuzhanghao · Feb 26, 2017 · b3d0e24 · b3d0e24
2 parents 860adc4 + 8fed678
commit b3d0e24
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diff --git a/group19/709960951/CodeLearning/src/com/coding/basic/ArrayList.java b/group19/709960951/CodeLearning/src/com/coding/basic/ArrayList.java
@@ -0,0 +1,109 @@
+package com.coding.basic;
+
+import java.util.Arrays;
+
+public class ArrayList implements List {
+	private static final int INI_SIZE = 100;
+	private static final int EXTENDED_SIZE = 100; // 每次扩容的大小
+	private int size = 0;
+	private Object[] elements = new Object[INI_SIZE];
+
+	@Override
+	public void add(int index, Object o) {
+		if (size < 1) {
+			index = 0;
+		} else {
+			if (index < 0) {
+				index = 0;
+			}
+			if (index > size - 1) {
+				index = size - 1;
+			}
+		}
+
+		ensureCapacity();
+		for (int i = size - 1; i >= index; i--) {
+			elements[i + 1] = elements[i];
+		}
+		elements[index] = o;
+		size++;
+	}
+
+	@Override
+	public void add(Object o) {
+		ensureCapacity();
+		elements[size] = o;
+		size++;
+	}
+
+	@Override
+	public Object get(int index) {
+		if (size < 1 || index < 0 || index > size - 1) {
+			throw new IndexOutOfBoundsException();
+		}
+		return elements[index];
+	}
+
+	@Override
+	public Object remove(int index) {
+		if (size < 1 || index < 0 || index > size - 1) {
+			throw new IndexOutOfBoundsException();
+		}
+		Object object = elements[index];
+		for (int i = index; i < size - 1; i++) {
+			elements[i] = elements[i + 1];
+		}
+		elements[size - 1] = null;
+		size--;
+		adjustCapacity(); // 调整数组至合适大小
+		return object;
+	}
+
+	@Override
+	public int size() {
+		return size;
+	}
+
+	// 底层数组最多有2*EXTENDED_SIZE个多余空间
+	private void adjustCapacity() {
+		if ((size + 2 * EXTENDED_SIZE) < elements.length) {
+			elements = Arrays.copyOf(elements, size + 2 * EXTENDED_SIZE);
+		}
+	}
+
+	// 每次添加元素时，检查底层数组的长度，保证存储空间
+	private void ensureCapacity() {
+		if (size == elements.length) {
+			elements = Arrays.copyOf(elements, elements.length + EXTENDED_SIZE);
+		}
+	}
+
+	public Iterator iterator() {
+		return new ArrayListIterator();
+	}
+
+	private class ArrayListIterator implements Iterator {
+
+		private int curIndex = 0;
+
+		@Override
+		public boolean hasNext() {
+			if (size > 0 && curIndex < size) {
+				return true;
+			}
+			return false;
+		}
+
+		@Override
+		public Object next() {
+			if (!hasNext()) {
+				throw new IndexOutOfBoundsException();
+			}
+			Object object = elements[curIndex];
+			curIndex++;
+			return object;
+		}
+
+	}
+
+}
diff --git a/group19/709960951/CodeLearning/src/com/coding/basic/Iterator.java b/group19/709960951/CodeLearning/src/com/coding/basic/Iterator.java
@@ -0,0 +1,6 @@
+package com.coding.basic;
+
+public interface Iterator {
+	boolean hasNext();
+	Object next();
+}
diff --git a/group19/709960951/CodeLearning/src/com/coding/basic/LinkedList.java b/group19/709960951/CodeLearning/src/com/coding/basic/LinkedList.java
@@ -0,0 +1,183 @@
+package com.coding.basic;
+
+public class LinkedList implements List {
+	private static class Node {
+		Object data;
+		Node next;
+	}
+
+	private int size = 0; // 初始化size=0
+	private Node head = null;
+
+	@Override
+	public void add(Object o) {
+		Node node = new Node();
+		node.data = o;
+		node.next = null;
+		if (head == null) {
+			head = node;
+		} else {
+			Node tail = head;
+			while (tail.next != null) {
+				tail = tail.next;
+			}
+			tail.next = node;
+		}
+		size++;
+	}
+
+	@Override
+	public void add(int index, Object o) {
+		if (size < 1) {
+			index = 0;
+		} else {
+			if (index < 0) {
+				index = 0;
+			}
+			if (index > size - 1) {
+				index = size - 1;
+			}
+		}
+		Node p = null;// 插入位置的前一节点
+		Node q = head;
+		while (index > 0) {
+			p = q;
+			q = q.next;
+			index--;
+		}
+		Node node = new Node();
+		node.data = o;
+		node.next = null;
+		if (p == null) {
+			node.next = head;
+			head = node;
+		} else {
+			node.next = p.next;
+			p.next = node;
+		}
+		size++;
+	}
+
+	@Override
+	public Object get(int index) {
+		if (index < 0 || index > size - 1) {
+			throw new IndexOutOfBoundsException();
+		}
+		Node p = head;
+		while (index > 0) {
+			p = p.next;
+			index--;
+		}
+		return p.data;
+	}
+
+	@Override
+	public Object remove(int index) {
+		if (index < 0 || index > size - 1) {
+			throw new IndexOutOfBoundsException();
+		}
+		Node removeObj;
+		Node p = null;
+		Node q = head;
+		while (index > 0) {
+			p = q;
+			q = q.next;
+			index--;
+		}
+		if (p == null) {
+			removeObj = head;
+			head = head.next;
+		} else {
+			removeObj = p.next;
+			p.next = removeObj.next;
+		}
+		size--;
+		return removeObj.data;
+	}
+
+	@Override
+	public int size() {
+		return size;
+	}
+
+	public void addFirst(Object o) {
+		Node node = new Node();
+		node.data = o;
+
+		node.next = head;
+
+		head = node;
+		size++;
+	}
+
+	public void addLast(Object o) {
+		Node node = new Node();
+		node.data = o;
+
+		if (head == null) {
+			head = node;
+		} else {
+			Node p = head;
+			while (p.next != null) {
+				p = p.next;
+			}
+			p.next = node;
+		}
+		size++;
+	}
+
+	public Object removeFirst() {
+		if (size < 1) {
+			throw new IndexOutOfBoundsException();
+		}
+		Node removeObj = head;
+		head = head.next;
+		size--;
+		return removeObj.data;
+	}
+
+	public Object removeLast() {
+		if (size < 1) {
+			throw new IndexOutOfBoundsException();
+		}
+		Node removeObj;
+		if (head.next == null) {
+			removeObj = head;
+			head = null;
+		} else {
+			Node p = head;
+			while (p.next.next != null) {
+				p = p.next;
+			}
+			removeObj = p.next;
+			p.next = null;
+		}
+		size--;
+		return removeObj.data;
+	}
+
+	public Iterator iterator() {
+		return new LinkedListIterator();
+	}
+
+	private class LinkedListIterator implements Iterator {
+
+		Node curNode = head;
+
+		@Override
+		public boolean hasNext() {
+			return curNode != null;
+		}
+
+		@Override
+		public Object next() {
+			if (!hasNext()) {
+				throw new IndexOutOfBoundsException();
+			}
+			Object object = curNode.data;
+			curNode = curNode.next;
+			return object;
+		}
+
+	}
+}
diff --git a/group19/709960951/CodeLearning/src/com/coding/basic/List.java b/group19/709960951/CodeLearning/src/com/coding/basic/List.java
@@ -0,0 +1,13 @@
+package com.coding.basic;
+
+public interface List {
+	void add(Object o);
+
+	void add(int index, Object o);
+
+	Object get(int index);
+
+	Object remove(int index);
+
+	int size();
+}
diff --git a/group19/709960951/CodeLearning/src/com/coding/basic/Queue.java b/group19/709960951/CodeLearning/src/com/coding/basic/Queue.java
@@ -0,0 +1,26 @@
+package com.coding.basic;
+
+public class Queue {
+
+	private LinkedList list = new LinkedList();
+
+	public void enQueue(Object o) {
+		list.addFirst(o);
+	}
+
+	public Object deQueue() {
+		if (isEmpty()) {
+			throw new IndexOutOfBoundsException();
+		}
+		Object object = list.removeLast();
+		return object;
+	}
+
+	public boolean isEmpty() {
+		return list.size() == 0;
+	}
+
+	public int size() {
+		return list.size();
+	}
+}
diff --git a/group19/709960951/CodeLearning/src/com/coding/basic/Stack.java b/group19/709960951/CodeLearning/src/com/coding/basic/Stack.java
@@ -0,0 +1,35 @@
+package com.coding.basic;
+
+
+public class Stack {
+
+	private ArrayList list=new ArrayList();
+	public void push(Object o)
+	{
+		list.add(o);
+	}
+	public Object pop()
+	{
+		if(isEmpty())
+		{
+			throw new IndexOutOfBoundsException();
+		}
+		return list.remove(list.size()-1);
+	}
+	public Object peak()
+	{
+		if(isEmpty())
+		{
+			throw new IndexOutOfBoundsException();
+		}
+		return list.get(list.size()-1);
+	}
+
+	public boolean isEmpty() {
+		return list.size()==0;
+	}
+
+	public int size() {
+		return list.size();
+	}
+}