我的函数：
import java.util.Collection;
import java.util.Collections;
public class LinkedList {
private Node head;
private int listCount;
// konstruktor na povrzanata lista
public LinkedList()
{
// ova e prazna lista, pa zatoa 'head' pokazuva kon nov jazok bez elementi (null)
head = new Node(null);
listCount = 0;
}
// dodavame element (data) na krajot od listata
public void add(Object data)
{
Node temp = new Node(data);
Node current = head;
head.setData(temp.getData());
// pocnuvajki od 'head' (pocetniot element) pominuvame niz site lemenenti
while(current.getNext() != null)
{
current = current.getNext();
}
current.setNext(temp);
// go zgolemuvame brojot na elementi vo listata
listCount++;
}
// dodavame element (data) na posebno opredelena pozicija (index)
public void add(Object data, int index)
{
Node temp = new Node(data);
Node current = head;
head.setData(temp.getData());
// odime do baraniot index, ili do posledniot element od listata (do koj stigneme prvo)
for (int i = 1; i < index && current.getNext() != null; i++)
{
current = current.getNext();
}
// go postavuvame sledniot element na novata jazla
// da pokazuva kon sledniot element na ovaa jazla
temp.setNext(current.getNext());
// a sega go postavuvame sledniot element na ovaa jazla
// da pokazuva kon novata jazla
current.setNext(temp);
// go nakacuvame vkupniot broj na elementi vo listata
listCount++;
}
// vraka element na opredelena pozicija vo listata
public Object get(int index)
{
if(index <= 0)
{
return null;
}
Node current = head.getNext();
for(int i = 1; i < index; i++)
{
if(current.getNext() == null)
{
return null;
}
current = current.getNext();
}
return current.getData();
}
// go vrakame brojot na elementi vo listata
public int size()
{
return listCount;
}
// go brisime elementot na opredelenata pozicija vo listata
public boolean remove(int index)
{
if(index < 1 || index > size())
{
return false;
}
Node current = head;
for(int i = 1; i < index; i++)
{
if(current.getNext() == null)
{
return false;
}
current = current.getNext();
}
current.setNext(current.getNext().getNext());
// go namaluvame brojot na elementi vo listata
listCount--;
return true;
}
public boolean contains(Object data)
{
Node temp = new Node(data);
Node current = head;
for(int i = 0; i < size(); i++)
{
if(temp.getData().equals(current.getData()))
{
return true;
}
else
{
current = current.getNext();
}
}
return false;
}
public Node inserAfter(Object data, Node n)
{
Node temp = new Node(data);
Node current = n.getNext();
temp.setNext(current);
n.setNext(temp);
return temp;
}
public void rotateLeft()
{
Node temp = head;
//head = head.getNext();
//Node tail = head.getNext();
if (head != null) { //otherwise it is empty list
//Node temp = head;
if (head.getNext() != null) { //otherwise it is single item list
head = head.getNext();
}
}
Node tail;
if (head.getNext() != null) {
//more than 2 items in the list
tail = head.getNext();
} else {
//only 2 items in the list
tail = head;
}
while(tail.getNext() != null)
{
if (tail.getNext() != null) {
tail = tail.getNext();
}
//tail = tail.getNext();
}
tail.setNext(temp);
temp.setNext(null);
}
public void rotateRight()
{
Node temp = null;
Node current = head;
while(current.getNext() != null)
{
temp = current;
current = current.getNext();
}
current.setNext(head);
head = current;
temp.setNext(null);
}
public void reverse()
{
Node reversedPart = null;
Node current = head;
while(current != null)
{
Node next = current.next;
current.next = reversedPart;
reversedPart = current;
current = next;
}
head = reversedPart;
}
public Node copyList(Node source)
{
Node copyHead = null;
Node copyTail = null;
Node temp = new Node(source);
Node current = head.getNext();
for(int i = 0; i < size(); i++)
{
Node newNode = new Node(temp.getData());
if(copyHead == null)
{
copyHead = newNode;
copyTail = copyHead;
}
else
{
copyTail.setNext(newNode);
copyTail = copyTail.getNext();
}
}
return copyHead;
}
public Object setDataIndexOf(Object data, int index)
{
Node node = nodeAt(index);
if(node == null)
{
return null;
}
else
{
Object old = node.getData();
node.setData(data);
return old;
}
}
public Object dataAt(int index)
{
Node current = head.getNext();
if(index < 1 || index > size())
{
return null;
}
for(int i = 0; i < index; i ++)
{
if(i != index - 1)
{
current = current.getNext();
}
}
return current.getData();
}
public Node nodeAt(int index)
{
Node current = head.getNext();
if(index < 1 || index > size())
{
return null;
}
for(int i = 0; i < index; i++)
{
if(i != index - 1)
{
current = current.getNext();
}
}
return current;
}
public int indexOf(Object data)
{
Node temp = new Node(data);
Node current = head.getNext();
for(int i = 0; i < size(); i++)
{
if(current.getData().equals(temp.getData()))
{
return i;
}
current = current.getNext();
}
return -1;
}
public Object min()
{
Integer min = (Integer)head.getData();
Node current = head;
while(current.getNext() != null)
{
if((Integer)current.getData() < min)
{
min = (Integer)current.getData();
}
current = current.getNext();
}
return min;
}
public Object max()
{
Integer max = (Integer)head.getData();
Node current = head;
while(current.getNext() != null)
{
if((Integer)current.getData() > max)
{
max = (Integer)current.getData();
}
current = current.getNext();
}
return max;
}
public void removeSecondAppear(Object data)
{
Node temp = new Node(data);
Node current = head;
Node previous = null;
boolean found = false;
while(current != null)
{
if(current.getData().equals(temp.getData()) && current.getData() != null)
{
if(found == true)
{
previous.setNext(current.getNext());
break;
}
else if(found == false)
{
found = true;
}
}
else{
found = false;
}
previous = current;
current = current.getNext();
}
}
public String toString()
{
Node current = head.getNext();
String output = "";
while(current != null)
{
output += "[" + current.getData().toString() + "]";
current = current.getNext();
}
return output;
}
}
我的节点：
public class Node {
Node next;
Object data;
public Node(Object _data)
{
next = null;
data = _data;
}
public Node(Object _data, Node _next)
{
next = _next;
data = _data;
}
public Object getData()
{
return data;
}
public void setData(Object _data)
{
data = _data;
}
public Node getNext()
{
return next;
}
public void setNext(Node _next)
{
next = _next;
}
}
我正在尝试创建一个函数来旋转Java中的单链接列表。我为左和右做了两个函数。
我的左侧功能似乎可以工作，但还不完全。例如如果我的列表包含以下元素：1 2 3
然后我的轮换左将使列表变成23。1将消失。但它应该是在前三名的基础上出现的。
至于rotateRight，由于某种原因，该功能无法正常运行，已经尝试了几个小时，但找不到解决方案。
LinkedList LL = new LinkedList();
LL.add("1");
LL.add("2");
LL.add("3");
LL.add("4");
LL.add("4");
LL.add("5");
LL.rotateLeft();
2，3，4，4，5，null为输出。我的添加方法如下：
public void add(Object data)
{
Node temp = new Node(data);
Node current = head;
while(current.getNext() != null)
{
current = current.getNext();
}
current.setNext(temp);
listCount++;
}
尝试此更正：
public void rotateLeft() {
if (head != null) { //otherwise it is empty list
Node temp = head;
if (head.getNext() != null) { //otherwise it is single item list
head = head.getNext();
}
Node tail;
if (head.getNext() != null) {
//more than 2 items in the list
tail = head.getNext();
} else {
//only 2 items in the list
tail = head;
}
while (tail.getNext() != null) {
if (tail.getNext() != null) {
tail = tail.getNext();
}
}
tail.setNext(temp);
temp.setNext(null);
}
}
public void rotateRight() {
if (head != null) { //otherwise it is empty list
Node tail = null;
Node current = head;
while (current.getNext() != null) {
tail = current;
current = current.getNext();
}
if (tail != null) { //otherwise it is single item list
tail.setNext(null);
current.setNext(head);
head = current;
}
}
}
您也没有处理空列表、单个项目列表或列表中只有2个项目的情况。
编辑：
代码：
public class LinkedList {
Node head;
public LinkedList() {
this.head = null;
}
public LinkedList(Node head) {
this.head = head;
}
public void rotateLeft() {
System.out.println("<-");
if (head != null) { // otherwise it is empty list
Node temp = head;
if (head.getNext() != null) { // otherwise it is single item list
head = head.getNext();
}
Node tail;
if (head.getNext() != null) {
// more than 2 items in the list
tail = head.getNext();
} else {
// only 2 items in the list
tail = head;
}
while (tail.getNext() != null) {
if (tail.getNext() != null) {
tail = tail.getNext();
}
}
tail.setNext(temp);
temp.setNext(null);
}
}
public void rotateRight() {
System.out.println("->");
if (head != null) { // otherwise it is empty list
Node tail = null;
Node current = head;
while (current.getNext() != null) {
tail = current;
current = current.getNext();
}
if (tail != null) { // otherwise it is single item list
tail.setNext(null);
current.setNext(head);
head = current;
}
}
}
public void printList() {
Node cursor = head;
while (cursor != null) {
System.out.print(cursor.data + ", ");
cursor = cursor.getNext();
}
System.out.println();
}
public void add(Object data) {
Node temp = new Node(data);
if (head == null) {
head = temp;
} else {
Node current = head;
while (current.getNext() != null) {
current = current.getNext();
}
current.setNext(temp);
}
}
public static void main(String[] args) {
LinkedList r = new LinkedList();
r.add(1);
r.add(2);
r.add(3);
r.add(4);
r.add(4);
r.add(5);
r.printList();
r.rotateLeft();
r.printList();
r.rotateLeft();
r.printList();
r.rotateRight();
r.printList();
r.rotateRight();
r.printList();
}
}
输出：
1, 2, 3, 4, 4, 5,
<-
2, 3, 4, 4, 5, 1,
<-
3, 4, 4, 5, 1, 2,
->
2, 3, 4, 4, 5, 1,
->
1, 2, 3, 4, 4, 5,