伙计们，我在从LinkedList中删除指定的Link时遇到了麻烦。例如，如果我有:
"A" --> "B" --> "C"
并且想要去除Link "B"，因此结果将是:
"A" --> "C"
我遇到了如何获得以前的Link "A"和参考"C"的麻烦。有人能帮我一下吗?方法是:
public void delete(String data){
if(isEmpty()){
System.out.println("The list is empty!");
System.exit(0);
}
else{
Link current = firstLink;
Link previous = firstLink;
while(current != null){
if(current.getData().equals(data)){
previous = current.getNext();
}
else{
previous = current;
current = current.getNext();
}
}
}
}
Link类
package LinkedList;
public class Link{
private String data;
private Link next;
public Link(String data){
this.data = data;
}
public void display(){
System.out.println(data);
}
public String getData(){
return this.data;
}
public Link getNext(){
return this.next;
}
}
class LinkedList{
private Link firstLink;
public LinkedList(){
this.firstLink = null;
}
public boolean isEmpty(){
return (this.firstLink == null);
}
public void insert(String data){
Link newLink = new Link(data);
Link newLinkNext = newLink.getNext();
newLinkNext = firstLink;
firstLink = newLink;
}
public Link deleteFirst(){
if(isEmpty()){
return null;
}
else {
Link deletedOne = this.firstLink;
Link nextLink = firstLink.getNext();
firstLink = nextLink;
return deletedOne;
}
}
public void delete(String data){
if(isEmpty()){
System.out.println("The list is empty!");
System.exit(0);
}
else{
Link current = firstLink;
Link previous = firstLink;
while(current != null){
if(current.getData().equals(data)){
previous = current.getNext();
}
else{
previous = current;
current = current.getNext();
}
}
}
}
伪代码:
prev = null;
current = first;
while not at the end of the list
{
if (current.data == the object I want) {
if (prev == null) {
first = current.next
break
}
prev.next = current.next
break;
}
prev = current
current = current.next
}
这里是一个示例，试图使其与您的代码相似
public class LinkedList {
private Node firstNode = null;
public LinkedList() {
}
public Node getFirstNode() {
return firstNode;
}
public void setFirstNode(Node firstNode) {
this.firstNode = firstNode;
}
public void addNode(Node node) {
if(firstNode == null){
firstNode = node;
}else{
Node walker = firstNode;
while(walker.getNext() != null)
walker = walker.getNext();
walker.setNext(node);
}
}
public void delete(int value) {
if (firstNode != null) {
Node walker = firstNode;
if (walker.getValue() == value) {
if(walker.getNext()!=null){
firstNode = walker.getNext();
}else{
setFirstNode(null);
}
} else {
Node previous = walker;
while (walker.getNext() != null) {
previous = walker;
walker = walker.getNext();
if (walker.getValue() == value) {
previous.setNext(walker.getNext());
break;
}
}
}
} else {
System.out.println("Nothing to delete");
}
}
public void listValues (){
if(firstNode != null){
Node walker = firstNode;
while(walker.getNext() != null)
{
System.out.println(walker.getValue());
walker = walker.getNext();
}
}
}
}
公共类Node {
private Node next = null;
private int value;
public Node(Node node, int value) {
this.next = node;
this.value = value;
}
public Node getNext() {
return next;
}
public void setNext(Node node) {
this.next = node;
}
public int getValue() {
return value;
}
public void setValue(int value) {
this.value = value;
}
}
模拟公共类{
public static void main(String[] args) {
LinkedList list = new LinkedList();
list.addNode(new Node(null, 1));
list.addNode(new Node(null, 2));
list.addNode(new Node(null, 3));
list.addNode(new Node(null, 4));
list.addNode(new Node(null, 123));
list.addNode(new Node(null, 5));
list.addNode(new Node(null, 6));
list.listValues();
list.delete(1);
System.out.println("-----");
list.listValues();
list.delete(123);
System.out.println("-----");
list.listValues();
list.addNode(new Node(null, 123));
list.addNode(new Node(null, 5));
list.delete(2);
System.out.println("-----");
list.listValues();
list.delete(26);
System.out.println("-----");
list.listValues();
}
}
和输出:123 4 123 5
2 3 4 123 5
2 3 4 5
3 4 5 6 123
3 4 5 6 123
对
class LLNode
{
int data;
LLNode next;
public LLNode(int data)
{
this.data=data;
}
}
public class DeleteNodeFromLinkedList
{
/* Link list node */
/* Given a reference (pointer to pointer) to the head
of a list and an int, push a new node on the front
of the list. */
public static void printList(LLNode head)
{
LLNode curr = head;
while(curr != null)
{
System.out.print(curr.data+" ");
curr = curr.next;
}
}
static void deleteNode(LLNode DelNode)
{
LLNode temp = DelNode.next;
DelNode.data = temp.data;
DelNode.next = temp.next;
}
/* Drier program to test above function*/
public static void main(String []args)
{
/* Start with the empty list */
LLNode head = new LLNode(1);
head.next = new LLNode(4);
head.next.next = new LLNode(4);
head.next.next.next = new LLNode(1);
head.next.next.next.next = new LLNode(12);
head.next.next.next.next.next = new LLNode(1);
System.out.println(" Before deleting ");
printList(head);
/* I m deleting the head.next
You can check for more cases */
deleteNode(head.next);
System.out.println(" n After deleting ");
printList(head);
}
}
不能在列表中操作(添加，删除…项目)，同时迭代它们。必须使用Iterator
for(Iterator<EmpDedup> iter = list.iterator(); iter.hasNext();) {
EmpDedup data = iter.next();
if (data.getRecord() == rec1) {
iter.remove();
}
}
见http://docs.oracle.com/javase/6/docs/api/java/util/Iterator.html