Work01 commit

group09/1271620150/Work01/.gitignore

@@ -0,0 +1,19 @@
+*.class
+*.classpath
+*.project
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.ear
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+
+#ide config
+.metadata
+.recommenders
+/bin/

group09/1271620150/Work01/src/com/coding/basic/ArrayList.java

@@ -0,0 +1,100 @@
+package com.coding.basic;
+
+import java.util.Arrays;
+import java.util.ConcurrentModificationException;
+import java.util.NoSuchElementException;
+
+public class ArrayList implements List {
+
+	private Object[] elements;
+
+	private int size;
+
+	public ArrayList(int initialCapacity) {
+		super();
+		if (initialCapacity < 0)
+			throw new IllegalArgumentException("Illegal Capacity: " + initialCapacity);
+		this.elements = new Object[initialCapacity];
+	}
+
+	public ArrayList() {
+		this(10);
+	}
+
+	public void add(Object obj) {
+		ensureCapacity(size + 1);
+		elements[size++] = obj;
+
+	}
+
+	public void add(int index, Object obj) {
+		rangeCheck(index);
+		ensureCapacity(size + 1);
+		System.arraycopy(elements, index, elements, index + 1, size - index);
+		elements[index] = obj;
+		size++;
+	}
+
+	public Object get(int index) {
+		rangeCheck(index);
+		return elements[index];
+	}
+
+	public Object remove(int index) {
+		rangeCheck(index);
+		Object toRemove = elements[index];
+		int numMoved = size - index - 1;
+		if (numMoved > 0)
+			System.arraycopy(elements, index + 1, elements, index, numMoved);
+		elements[--size] = null;
+		return toRemove;
+	}
+
+	public int size() {
+		return size;
+	}
+
+	public Iterator iterator() {
+		return new ArrayListIterator();
+	}
+
+	private void ensureCapacity(int minCapacity) {
+		int oldCapacity = elements.length;
+		if (minCapacity > oldCapacity) {
+			int newCapacity = oldCapacity * 2;
+			if (newCapacity < minCapacity)
+				newCapacity = minCapacity;
+			elements = Arrays.copyOf(elements, newCapacity);
+		}
+	}
+
+	private void rangeCheck(int index) {
+		if (index >= size)
+			throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
+	}
+
+	private String outOfBoundsMsg(int index) {
+		return "Index: " + index + ", Size: " + this.size;
+	}
+
+	private class ArrayListIterator implements Iterator{
+
+        private int pos = 0;
+
+        public boolean hasNext() {
+            return pos != size;
+        }
+
+        public Object next() {
+        	int i = pos;
+        	if (i >= size)
+                throw new NoSuchElementException();
+            Object[] elements = ArrayList.this.elements;
+            if (i >= elements.length)
+                throw new ConcurrentModificationException();
+            pos = i + 1;
+            return (Object) elements[i];
+        }
+    }
+
+}

group09/1271620150/Work01/src/com/coding/basic/Iterator.java

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