arraylist

hongxin230 · hongxin230 · commit 64bae7c49104 · 2017-02-26T22:34:38.000+08:00
diff --git a/group05/1094051862/test01/src/com/coding/basic/ArrayList.java b/group05/1094051862/test01/src/com/coding/basic/ArrayList.java
@@ -0,0 +1,79 @@
+package com.coding.basic;
+
+import java.util.Arrays;
+
+public class ArrayList implements List {
+	
+	private int size = 0;
+	
+	private Object[] elementData = new Object[10];
+	
+	private int increaseSize = 3;
+	private void increaseArray() {
+		Object[] newData = Arrays.copyOf(elementData, elementData.length + increaseSize);
+		elementData = newData;
+	}
+	public void add(Object o){
+		if (size == elementData.length) {
+			increaseArray();
+			elementData[size++] = o;
+		} else {
+			elementData[size++] = o;
+		}
+	}
+	public void add(int index, Object o){
+		if (index < 0 || index > size) {
+			System.out.println("错误提示：index > size || index < 0");
+			return;
+		}
+		Object temp;
+		for (int i = index; i < size; i++) {
+			temp = elementData[i];
+			elementData[i] = o;
+			o = temp;
+		}
+		elementData[size ++] = o;
+	}
+	
+	public Object get(int index){
+		if (index < 0 || index > size ){
+			return null;
+		}
+		return elementData[index];
+	}
+	
+	public Object remove(int index){
+		if (index < 0 || index > size ){
+			return null;
+		}
+		Object result = elementData[index];
+		for (int i = index; i < size-1; i++) {
+			elementData[i] = elementData[i + 1];
+		}
+		elementData[size-1] = null;
+		size --;
+		return result;
+	}
+	
+	public int size(){
+		return size;
+	}
+	
+	public Iterator iterator(){
+		return new Iterator() {
+			private int cusor = 0;
+			@Override
+			public Object next() {
+				if (!hasNext()) {
+					System.out.println("next: !hasNext");
+					return null;
+				}
+				return elementData[cusor ++];
+			}
+			@Override
+			public boolean hasNext() {
+				return cusor < size;
+			}
+		};
+	}
+}
