java数据结构：线性表之数组实现

• 导语

      数据结构中最简单的结构就是线性结构。

      线性结构又分为多种类型：顺序线性表、链式线性表、栈、队列、堆等等

      今天我们来复习一下如何使用数组来实现线性表

• 设计抽象数据类型ADT

      数据结构实际上就是针对一系列数据，设计一系列针对这些数据的操作方法，由于这些数据和操作方法一般来说是共性的特征，所以我们可以使用接口来进行抽象。接口代码如下所示：

package com.zhanwj.datastructure;public interface ListInterface {/** * @return the size of the list */public int getSize();/** * @return  * if null then return true,else return false */public boolean isEmpty();/** * @param mObject the object that wanted to be  * confirm whether it is contained in the list * @return if the list contains the object then return true  */public boolean contains(Object mObject);/** * return the index of object in the list * @param mObject * @return  the index */public int indexOf(Object mObject);/** * insert element into the list * @param ithe place to insert * @param mObjectthe element to insert */public void insert(int i,Object mObject) throws OutOfBoundaryException;/** * insert the element before the mObject * @param mObject * @param element */public boolean insertBefore(Object mObject,Object element);/** * insert the element after the mObject * @param mObject * @param element */public boolean insertAfter(Object mObject,Object element);/** * remove the element whose index is i * @param i * @returnobject */public Object remove(int i) throws OutOfBoundaryException;/** * remove the object that same as mObject at the first time * @param mObject * @return */public boolean remove(Object mObject);/** * replace the element whose index is i with mObject  * @param i * @param mObject * @return */public Object replace(int i,Object mObject) throws OutOfBoundaryException;/** * return the element whose index is i * @param i * @return */public Object get(int i) throws OutOfBoundaryException;}

      分析：在此接口中，声明了常用的线性表操作函数，最主要的就是插入数据、删除数据、替换数据等等

• 设计顺序线性表类

      设计好抽象数据类型接口之后，就如我们今天复习的主题，使用Array来实现线性表，则定义一个类，implements上面的接口，在类中数据域须为数组，实现接口中声明的操作方法来对数组中的数据进行操作。

顺序线性表ListArray类文件代码，如下所示：

package com.zhanwj.datastructure;/** * use array to implement the list * @author wenjerzhan * */public class ListArray implements ListInterface {/** * the default length of the array */private final int LENGTH = 8;/** * the size of the list */private int size;/** * the array definition */private Object[] elements;private CompareInterface mCompareInterface;public ListArray(CompareInterface compareInterface){this.mCompareInterface = compareInterface;this.size = 0;this.elements = new Object[LENGTH];}@Overridepublic int getSize() {return size;}@Overridepublic boolean isEmpty() {return size==0;}@Overridepublic boolean contains(Object mObject) {for (int i = 0; i < size; i++) {if (this.mCompareInterface.equal(mObject, (Object)elements[i])) return true;}return false;}@Overridepublic int indexOf(Object mObject) {for (int i = 0; i < size; i++) {if (this.mCompareInterface.equal(mObject, elements[i])) return i;}return -1;}@Overridepublic void insert(int i, Object mObject) throws OutOfBoundaryException {if (i < 0||i > size ) throw new OutOfBoundaryException("error,out of the list boundary");if (size >= elements.length)addArrayLength();for (int j = size; j >i; j--) elements[j] = elements[j-1];elements[i] = mObject;size++;}private void addArrayLength(){Object[] temp = new Object[elements.length*2];for (int i = 0; i < elements.length; i++) {temp[i] = elements[i];}elements = temp;}@Overridepublic boolean insertBefore(Object mObject, Object element) {int index = indexOf(mObject);if (index < 0 ) return false;insert(index, element);return true;}@Overridepublic boolean insertAfter(Object mObject, Object element) {int index = indexOf(mObject);if (index < 0)return false;insert(index+1, element);return true;}@Overridepublic Object remove(int i) throws OutOfBoundaryException {if (i <0 ||i>= size) throw new OutOfBoundaryException("error,out of the boundary");Object mObject = elements[i];for (int j = i; j < size-1; j++) {elements[j] = elements[j+1];}elements[--size] = null;return mObject;}@Overridepublic boolean remove(Object mObject) {int index = indexOf(mObject);if (index < 0 )return false;remove(index);return true;}@Overridepublic Object replace(int i, Object mObject) throws OutOfBoundaryException {if (i <0 ||i>= size) throw new OutOfBoundaryException("error,out of the boundary");Object temp = elements[i];elements[i] = mObject;return temp;}@Overridepublic Object get(int i) throws OutOfBoundaryException {if (i <0 ||i>= size) throw new OutOfBoundaryException("error,out of the boundary");return elements[i];}}

      备注：注意各操作方法实现的顺序，有些方法的实现需要调用其他方法

• 类文件UML视图

• 测试代码

package com.zhanwj.datastructure;public class ListArrayTest {public static void main(String[] args) throws Exception{CompareInterface compareInterface = new CompareInterface() {@Overridepublic boolean equal(Object mObject1, Object mObject2) {if (mObject1.equals(mObject2))return true;return false;}@Overridepublic int compare(Object mObject1, Object mObject2) {return mObject1.toString().compareTo(mObject2.toString());}};ListArray mListArray = new ListArray(compareInterface);final int LENGTH = 8;int num = 11;/** * test the getSize() function */System.out.println("====before insert operation,the size of the list is "+mListArray.getSize());/** * test the isEmpty() function */String isEmptyTest = mListArray.isEmpty()?"empty":"not empty";System.out.println("====before insert operation ,the list is "+isEmptyTest);/** * test the insert(i,object) function */for (int i = 0; i < LENGTH; i++) {mListArray.insert(i, ++num);System.out.println("insert into position "+(i+1)+" with value of "+num);}System.out.println("after insert operation,the size of the list is "+mListArray.getSize());/** * test the contains(object) function */String contains = mListArray.contains((Object)14)?"contain":"not contain";String notContains = mListArray.contains((Object)11)?"contain":"not contain";System.out.println("====the value 14 "+contains+" in the list");System.out.println("the value 11 "+notContains+" in the list");/** * test the indexOf(Object) function */System.out.println("====the index of 13 is "+ (mListArray.indexOf((Object)13)+1));/** * test the insertBefore(object1,object2) function */mListArray.insertBefore(14, 44);System.out.println("====insert 44 before 14!");System.out.print("the list is:");for (int i = 0; i < mListArray.getSize(); i++) {System.out.print(mListArray.get(i)+"\t");}System.out.println();/** * test the insertAfter(object1,object2) function */mListArray.insertAfter(14, 45);System.out.println("====insert 45 after 14!");System.out.print("the list is:");for (int i = 0; i < mListArray.getSize(); i++) {System.out.print(mListArray.get(i)+"\t");}System.out.println();/** * test the remove(i) function */mListArray.remove(7);System.out.print("====after remove,the list is:");for (int i = 0; i < mListArray.getSize(); i++) {System.out.print(mListArray.get(i)+"\t");}System.out.println();/** * test the replace(i,object) function */mListArray.replace(7, 23);System.out.print("====after replace,the list is:");for (int i = 0; i < mListArray.getSize(); i++) {System.out.print(mListArray.get(i)+"\t");}}}

     测试代码运行结果：====before insert operation,the size of the list is 0
====before insert operation ,the list is empty
insert into position 1 with value of 12
insert into position 2 with value of 13
insert into position 3 with value of 14
insert into position 4 with value of 15
insert into position 5 with value of 16
insert into position 6 with value of 17
insert into position 7 with value of 18
insert into position 8 with value of 19
after insert operation,the size of the list is 8
====the value 14 contain in the list
the value 11 not contain in the list
====the index of 13 is 2
====insert 44 before 14!
the list is:12 13  44  14  15  16  17  18  19
====insert 45 after 14!
the list is:12 13  44  14  45  15  16  17  18  19
====after remove,the list is:12  13  44  14  45  15  16  18  19
====after replace,the list is:12  13  44  14  45  15  16  23  19