第一周作业

group24/494800949/.gitignore

@@ -0,0 +1,4 @@
+.idea/*
+*.iml
+build/*
+.gradle/*

group24/494800949/build.gradle

@@ -0,0 +1,29 @@
+group 'com.hpe'
+version '1.0'
+
+buildscript {
+    repositories {
+        mavenCentral()
+    }
+}
+apply plugin: 'java'
+apply plugin: 'idea'
+
+sourceCompatibility = 1.8
+sourceCompatibility = 1.8
+
+repositories {
+    mavenCentral()
+}
+
+dependencies{
+    compile group: 'junit', name: 'junit', version: '4.11'
+}
+gradle.projectsEvaluated {
+    tasks.withType(JavaCompile) {
+        options.compilerArgs << "-Xlint:unchecked"
+        options.encoding = "UTF-8"
+    }
+}
+
+defaultTasks "build"

group24/494800949/src/main/java/com/coding/weak1/ArrayList.java

@@ -0,0 +1,102 @@
+package com.coding.weak1;
+
+public class ArrayList implements List {
+
+	private int size = 0;
+
+	private Object[] elementData = new Object[100];
+
+	public void add(Object o){
+		ensureCapcity(size + 1);
+		elementData[size++] = o;
+	}
+
+	/**
+	 * 当数组长度不够时进行扩容
+	 */
+	private void ensureCapcity(int requireSize){
+		int oldCapacity = elementData.length;
+		int newCapacity ;
+		if(oldCapacity < requireSize){
+			newCapacity = oldCapacity + (oldCapacity >> 1);
+
+			if(newCapacity < 0){
+				newCapacity = Integer.MAX_VALUE;
+			}
+
+            if(newCapacity > Integer.MAX_VALUE - 8){
+				newCapacity = Integer.MAX_VALUE;
+			}
+
+			Object[] elementDataNew = new Object[newCapacity];
+			System.arraycopy(elementData, 0, elementDataNew, 0, oldCapacity);
+			elementData = elementDataNew;
+		}
+	}
+
+
+	public void add(int index, Object o){
+		indexCheckForAdd(index);
+        ensureCapcity(index + 1);
+        Object[] newElementData = new Object[elementData.length];
+        if(index > 0)
+            System.arraycopy(elementData, 0, newElementData, 0, index-1);
+        System.arraycopy(elementData, index, newElementData, index+1, size-index);
+        elementData = newElementData;
+        elementData[index] = o;
+        size++;
+	}
+
+
+    private void indexCheckForAdd(int index) {
+        if(index < 0 || index >= size-1){
+           throw new IndexOutOfBoundsException("max index is: "+(size-1));
+        }
+    }
+
+    public Object get(int index){
+        indexCheck(index);
+		return elementData[index];
+	}
+
+    private void indexCheck(int index) {
+        if(index < 0 || index > size-1){
+            throw new IndexOutOfBoundsException("max index is: "+(size-1));
+        }
+    }
+
+    public Object remove(int index){
+        indexCheck(index);
+        Object obj = elementData[index];
+        System.arraycopy(elementData, index+1, elementData, index, size-index-1);
+        elementData[size--] = null;
+		return obj;
+	}
+
+	public int size(){
+		return size;
+	}
+
+	public Iterator iterator(){
+		return new ListIter();
+	}
+
+    private class ListIter implements Iterator{
+
+        private int cursor;
+
+        @Override
+        public boolean hasNext() {
+            return cursor < size;
+        }
+
+        @Override
+        public Object next() {
+            int index = cursor;
+            if(index >= size)
+                throw new IndexOutOfBoundsException();
+            cursor++;
+            return elementData[index];
+        }
+    }
+}

group24/494800949/src/main/java/com/coding/weak1/BinaryTreeNode.java

@@ -0,0 +1,32 @@
+package com.coding.weak1;
+
+public class BinaryTreeNode {
+
+	private Object data;
+	private BinaryTreeNode left;
+	private BinaryTreeNode right;
+
+	public Object getData() {
+		return data;
+	}
+	public void setData(Object data) {
+		this.data = data;
+	}
+	public BinaryTreeNode getLeft() {
+		return left;
+	}
+	public void setLeft(BinaryTreeNode left) {
+		this.left = left;
+	}
+	public BinaryTreeNode getRight() {
+		return right;
+	}
+	public void setRight(BinaryTreeNode right) {
+		this.right = right;
+	}
+
+	public BinaryTreeNode insert(Object o){
+		return  null;
+	}
+
+}

group24/494800949/src/main/java/com/coding/weak1/Iterator.java

@@ -0,0 +1,7 @@
+package com.coding.weak1;
+
+public interface Iterator {
+	public boolean hasNext();
+	public Object next();
+
+}