数据结构系列之链表

</pre><pre name="code" class="java">package 单链表;//组成链表的节点类public class IntNode {    public int value;public IntNode next;public IntNode(int value){this(value,null);      //调用下面的一个构造函数}public IntNode(int value,IntNode next){this.value=value;this.next=next;}}

2、再创建链表类

package 单链表;//单链链表类public class IntSLList {private IntNode head,tail;private int length;public int getLength() {return length;}public IntSLList(){      //构造函数，初始化head和tail,length;this.head=null;this.tail=null;length=0;}public boolean isEmpty(){   //判断是否为空链表return head==null;}public void addToHead(int value){   //在head节点前插入值为value的新节点head=new IntNode(value,head);if(tail==null){tail=head;}length++;}public void addToTail(int value){  //在tail节点后插入值为value的新节点if(this.isEmpty())head=tail=new IntNode(value);else{tail.next=new IntNode(value);tail=tail.next;}length++;}public int deleteFromHead(){    //删除头节点，返回头节点value信息int value=head.value;if(head==tail)head=tail=null;elsehead=head.next;length--;return value;}public int deleteFromTail(){int value=tail.value;if(head==tail)head=tail=null;else{IntNode temp;for(temp=head;temp.next!=tail;temp=temp.next);  //空循环，旨在移动temptail=temp;tail.next=null;}length--;return value;}public void printAll(){if(this.isEmpty())System.out.println("单链表为空！");else{IntNode temp=head;System.out.print("单链表为：");    while(temp!=null){System.out.print(temp.value+"  ");temp=temp.next;    }    System.out.println();}}public boolean isInList(int value){IntNode temp=head;boolean b=false;while(temp!=null){if(temp.value==value){b=true;break;}temp=temp.next;}return b;}public void deleteByValue(int value){ //根据节点值删除节点int flag=0;    if(head.value==value&&head==tail){      //如果只有一个节点    head=tail=null;    flag=1;    }          else if(head.value==value){            //不止一个节点，但目地节点在头节点    head=head.next;    flag=1;        }    else{                                  //不止一个节点，目地节点不再头节点       IntNode temp,pred;       for(pred=head,temp=head.next;temp!=null&&temp.value!=value;temp=temp.next,pred=pred.next);       if(temp!=null){       pred.next=temp.next;       flag=1;       }        }    if(flag==1){    System.out.println("元素"+value+"删除成功！");    length--;    }    else    System.out.println("元素"+value+"不再链表中！");}public int deleteByIndex(int index){  //根据下标删除节点int deleteValue=index;if(this.isEmpty()){System.out.print("空链表，无法进行删除操作！");return deleteValue;}else if(index>-1&&index<this.length){if(index==0)deleteValue=this.deleteFromHead();else if(index==this.length-1)deleteValue=this.deleteFromTail();else{IntNode temp=head;int i=0;for(i=0;i<index-1;i++){temp=temp.next;}deleteValue=temp.next.value;temp.next=temp.next.next;length--;}}else{System.out.println("下标越界");}return deleteValue;}    public void reverseList(){         //反转链表    IntNode p=head,q=null,r=null,m=null;    if(!this.isEmpty()){    if(this.length==1)    q=p;    else if(this.length==2){    q=p.next;    q.next=p;    p.next=null;    }    else{    q=p.next;    r=q.next;    while(q!=null&&r!=null){    q.next=p;    p.next=m;    m=p;    p=q;    q=r;    r=r.next;    }    q.next=p;    }    head=q;    }    else{    System.out.println("链表为空！");    }    }    public void insertByValue(int value,int insertValue){  //在value前插入insertValue    if(this.isInList(value)){    IntNode p=head,q=null;    if(p.value==value)    this.addToHead(insertValue);    else{    q=p.next;    while(q!=null){    if(q.value==value)    break;    else{    q=q.next;    p=p.next;    }    }    IntNode valueNode=new IntNode(insertValue);    valueNode.next=q;    p.next=valueNode;        length++;    }    }    else{    System.out.print("元素"+value+"不在链表中！");    }    }    public void insertByIndex(int index,int insertValue){    if(!this.isEmpty()){    if(index>-1&&index<this.length){    if(index==0)    this.addToHead(insertValue);    else{    IntNode p=head,q=null;    int j=0;    for(j=0;j<index-1;j++)    p=p.next;    q=p.next;    IntNode insertNode=new IntNode(insertValue);    insertNode.next=q;    p.next=insertNode;    length++;    }    }    else    System.out.print("下标越界！");    }    else    System.out.print("链表为空！");    }}

3、最后创建测试类

<span style="font-size:12px;">package 单链表;//测试类public class Test {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubIntSLList l=new IntSLList();IntSLList m=new IntSLList();                //测试isEmpty()System.out.println(l.isEmpty());l.addToHead(1);System.out.println(l.isEmpty());//测试getLength()System.out.println(l.getLength());System.out.println(m.getLength());//测试printAll()l.printAll();m.printAll();//测试addToHead(int value)l.addToHead(2);l.printAll();//测试deleteFromHead()int dele=l.deleteFromHead();System.out.println("删除元素为："+dele);l.printAll();int dele1=l.deleteFromHead();System.out.println("删除元素为："+dele1);l.printAll();//测试addToTail(int value)m.addToTail(1);m.addToTail(2);m.printAll();//测试deleteByIndex(int index)m.deleteByIndex(0);m.printAll();m.deleteByIndex(0);m.printAll();m.addToTail(1);m.addToTail(2);m.addToTail(3);m.addToTail(4);m.printAll();m.deleteByIndex(1);m.printAll();m.deleteByIndex(2);m.printAll();m.deleteByIndex(2);m.printAll();}}</span><strong style="font-size:10px;"></strong>