I have a task for double link insert algorithm,I have spent a lot time on doing it but still failed,the sortLink method still can not work,could anyone help me how to solve it?The code is listed as below:
Link.java：
public class Link {
private int value;
private Link next;
private Link prev;
public int getValue() {
return value;
}
public void setValue(int value) {
this.value = value;
}
public Link getNext() {
return next;
}
public void setNext(Link next) {
this.next = next;
}
public Link getPrev() {
return prev;
}
public void setPrev(Link prev) {
this.prev = prev;
}
}
Test.java
public class Test {
public static void main(String[] args) {
testLink();
}
public static void sortLink(Link headLink){
Link curLink=null,preLink=null,nextLink=null,link=null,pLink=null;
curLink=headLink.getNext();
headLink.setNext(null);
headLink.setPrev(null);
while(curLink!=null){
pLink=curLink;
link=curLink.getNext();
if(curLink.getValue()<headLink.getValue()){
curLink.setNext(headLink);
curLink.setPrev(headLink.getPrev());
headLink=curLink;
}else{
preLink=headLink;
nextLink=headLink.getNext();
while(nextLink!=null&&nextLink.getValue()<curLink.getValue()){
preLink=nextLink;
nextLink=nextLink.getNext();
curLink.setPrev(pLink);
}
curLink.setNext(preLink.getNext());
preLink.setNext(curLink);
}
curLink=link;
}
showFE(headLink);
//showEF(curLink);
}
public static void testLink(){
Link link1=new Link();
link1.setValue(7);
Link link2=new Link();
link2.setValue(3);
Link link3=new Link();
link3.setValue(1);
Link link4=new Link();
link4.setValue(2);
Link link5=new Link();
link5.setValue(9);
Link link6=new Link();
link6.setValue(6);
Link link7=new Link();
link7.setValue(4);
Link link8=new Link();
link8.setValue(8);
Link link9=new Link();
link9.setValue(5);
link1.setNext(link2);
link1.setPrev(null);
link2.setNext(link3);
link2.setPrev(link1);
link3.setNext(link4);
link3.setPrev(link2);
link4.setNext(link5);
link4.setPrev(link3);
link5.setNext(link6);
link5.setPrev(link4);
link6.setNext(link7);
link6.setPrev(link5);
link7.setNext(link8);
link7.setPrev(link6);
link8.setNext(link9);
link8.setPrev(link7);
link9.setPrev(link8);
link9.setNext(null);
showFE(link1);
//showEF(link9);
sortLink(link1);
}
//show node from front to end
public static void showFE(Link link){
while(link!=null){
System.out.print(link.getValue()+"-->");
link=link.getNext();
}
System.out.println();
}
//从尾至头显示链表
// public static void showEF(Link link){
// while(link!=null){
// System.out.print(link.getValue()+"<--");
// link=link.getPrev();
// }
// System.out.println();
// }
}
The main method is sortLink,I have tried but I am not able to run this program correctly,
it can output the result in order,but the relation between each link is not correct,so if we want to insert or remove some link,or show link from end to front, it will wrong.
could anyone help me with correcting the insert algorithm?
Related
I tried to write a udf function to calculate my data. In the trino's docs, I knew I should to write a function plugin and I succeed to execute my udf aggregate function sql.
But when I write sql with aggregate function and window function, the sql executed failed.
The error log is com.google.common.util.concurrent.ExecutionError: java.lang.NoClassDefFoundError: com/example/ListState.
I think I may implement the interface about the window function.
The ListState.java file code
#AccumulatorStateMetadata(stateSerializerClass = ListStateSerializer.class, stateFactoryClass = ListStateFactory.class)
public interface ListState extends AccumulatorState {
List<String> getList();
void setList(List<String> value);
}
The ListStateSerializer file code
public class ListStateSerializer implements AccumulatorStateSerializer<ListState>
{
#Override
public Type getSerializedType() {
return VARCHAR;
}
#Override
public void serialize(ListState state, BlockBuilder out) {
if (state.getList() == null) {
out.appendNull();
return;
}
String value = String.join(",", state.getList());
VARCHAR.writeSlice(out, Slices.utf8Slice(value));
}
#Override
public void deserialize(Block block, int index, ListState state) {
String value = VARCHAR.getSlice(block, index).toStringUtf8();
List<String> list = Arrays.asList(value.split(","));
state.setList(list);
}
}
The ListStateFactory file code
public class ListStateFactory implements AccumulatorStateFactory<ListState> {
public static final class SingleListState implements ListState {
private List<String> list = new ArrayList<>();
#Override
public List<String> getList() {
return list;
}
#Override
public void setList(List<String> value) {
list = value;
}
#Override
public long getEstimatedSize() {
if (list == null) {
return 0;
}
return list.size();
}
}
public static class GroupedListState implements GroupedAccumulatorState, ListState {
private final ObjectBigArray<List<String>> container = new ObjectBigArray<>();
private long groupId;
#Override
public List<String> getList() {
return container.get(groupId);
}
#Override
public void setList(List<String> value) {
container.set(groupId, value);
}
#Override
public void setGroupId(long groupId) {
this.groupId = groupId;
if (this.getList() == null) {
this.setList(new ArrayList<String>());
}
}
#Override
public void ensureCapacity(long size) {
container.ensureCapacity(size);
}
#Override
public long getEstimatedSize() {
return container.sizeOf();
}
}
#Override
public ListState createSingleState() {
return new SingleListState();
}
#Override
public ListState createGroupedState() {
return new GroupedListState();
}
}
Thanks for help!!!!
And I found the WindowAccumulator class in the trino source code. But I don't know how to use it.
How to create a aggregate function for window function?
*Using the ArrayBoundedStack class,create an application named EditNumbers that prompts the user for a set of five integer numbers, push its content into a stack, and then repeatedly prompts the user for changes to numbers, until the user enters an X, indicating the end of changes. Legal change operations are: M, A, R, and C.
• Option M return the maximum value in the set
• Option A v1 means add v1 to each number in the set
• Option R means reverse the numbers in the set
• Option C v1 v2 means change all occurrences of v1 to v2
*
(arrayboundedstack) using this codes bellow
**1)** package stack;
public class ArrayBoundedStack <T> implements StackInterface <T> {
private final int DEFSIZE=100;
private int index=-1;
private T[] arr;
public ArrayBoundedStack()
{
arr=(T[])new Object[DEFSIZE];
}
public ArrayBoundedStack(int size)
{
arr=(T[])new Object[size];
}
public boolean isFull()
{
return index == (arr.length-1);
}
public boolean isEmpty()
{
return index == -1;
}
public void push(T element)
{
if(!isFull())
{
index++;
arr[index]=element;
}
else{
throw new OverflowStackException("The stack is fill , you cannot push");
}
}
public void pop()
{
if(!isEmpty())
{
arr[index]=null;
index--;
}
else{
throw new UnderflowStackException("The stack is empty , you cannot pop");
}
}
public T top()
{
T temp=null;
if (!isEmpty())
temp=arr[index];
else{
throw new UnderflowStackException("The stack is empty , there is no top");
}
return temp;
}
}
**2) ** package stack;
public class MyApp1 {
public static void printStack(ArrayBoundedStack<Integer> st)
{
ArrayBoundedStack<Integer> temp=new ArrayBoundedStack<>(10);
System.out.println("the stack contains:");
while(!st.isEmpty())
{
System.out.println(st.top());
temp.push(st.top());
st.pop();
}
while(!temp.isEmpty())
{
st.push(temp.top());
temp.pop();
}
}
public static void nonNegativeStack(ArrayBoundedStack<Integer> st)
{
ArrayBoundedStack<Integer> temp=new ArrayBoundedStack<>();
while(!st.isEmpty())
{
if(st.top()>=0)
temp.push(st.top());
st.pop();
}
while(!temp.isEmpty())
{
st.push(temp.top());
temp.pop();
}
}
public static void main(String[] args)
{
ArrayBoundedStack<Integer> st=new ArrayBoundedStack<>(10);
st.push(10);
st.push(15);
st.push(30);
printStack(st);
System.out.println("the top of stack is " + st.top());
st.pop();
st.pop();
st.pop();
System.out.println("the top of stack is " + st.top());
}
}
**3) ** package stack;
public class MyApp2 {
public static void main(String[] args)
{
System.out.println("This is a test for exception");
throw new OverflowStackException("the stack is full");
}
}
**4)** package stack;
public class OverflowStackException extends RuntimeException{
public OverflowStackException()
{
super();
}
public OverflowStackException(String msg)
{
super(msg);
}
}
**5) ** package stack;
public interface StackInterface <T> {
public void push(T element) throws OverflowStackException;
public void pop() throws UnderflowStackException;
public T top()throws UnderflowStackException;
public boolean isFull();
public boolean isEmpty();
}
**6)**package stack;
public class UnderflowStackException extends RuntimeException{
public UnderflowStackException()
{
super();
}
public UnderflowStackException(String msg)
{
super(msg);
}
}
i made all the class up and i didnt know how to make a main class
I have a recyclerview with a header achieved by using two different element types. In my header there is an edit text which I want to use for filtering the nonheader elements of the list. Below is my current implementation, I have one concern and one problem with it.
My concern is that what I am doing in publishResults with the notifyItemRangeRemoved and notifyItemInserted is the wrong way to update the recycler view. I originally was doing notifyDatasetChanged but his would cause the header row to be refreshed too and the edit text to lose focus. What I really want is a way to refresh only the item rows and leave the header row untouched.
My current problem is that with the existing code if I scroll down too much the edit text looses focus. I want the edit text to keep focus even if I scroll to the bottom of the list.
The code used to use a ListView with setHeaderView and that worked somehow so there must be someway of achieving the goal just not sure what the trick with a recycler view is. Any help is much appreciated.
public class SideListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements Filterable {
private static final int TYPE_HEADER = 0;
private static final int TYPE_ITEM = 1;
private final List<String> data;
public List<String> filteredData;
private HeaderActionListener headerActionListener;
public SideListAdapter(Context context, ArrayList<String> data, HeaderActionListener headerActionListener) {
this.data = data;
filteredData = new ArrayList<>(data);
this.context = context;
this.headerActionListener = headerActionListener;
}
#Override
public Filter getFilter() {
return new TestFilter();
}
static class SideListItem extends RecyclerView.ViewHolder {
LinearLayout baseLayout;
public SideListItem(View itemView) {
super(itemView);
baseLayout = (LinearLayout) itemView.findViewById(R.id.settings_defaultcolor);
}
}
class SideListHeader extends SideListHeader {
EditText sort;
public SideListHeaderLoggedIn(View itemView) {
super(itemView);
sort = (EditText) itemView.findViewById(R.id.sort);
}
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_ITEM) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
return new SideListItem(v);
} else if (viewType == SideListHeader) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.header, parent, false);
return new SideListHeader(v);
}
throw new RuntimeException("there is no type that matches the type " + viewType + " + make sure your using types correctly");
}
public interface HeaderActionListener {
boolean onSortEditorAction(TextView arg0, int arg1, KeyEvent arg2);
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
if (holder instanceof SideListHeader) {
final SideListHeader sideListHeader = (SideListHeader) holder;
sideListHeader.sort.setOnEditorActionListener(new TextView.OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
}
});
sideListHeader.sort.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {
}
#Override
public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
}
#Override
public void afterTextChanged(Editable editable) {
String result = sideListHeader.sort.getText().toString().replaceAll(" ", "");
getFilter().filter(result);
}
});
}
if (holder instanceof SideListItem) {
// Inflate normal item //
}
}
// need to override this method
#Override
public int getItemViewType(int position) {
if (isPositionHeader(position)) {
return TYPE_HEADER;
}
return TYPE_ITEM;
}
private boolean isPositionHeader(int position) {
return position == 0;
}
//increasing getItemcount to 1. This will be the row of header.
#Override
public int getItemCount() {
return filteredData.size() + 1;
}
private class TestFilter extends Filter {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
FilterResults results = new FilterResults();
String prefix = constraint.toString().toLowerCase();
if (prefix.isEmpty()) {
ArrayList<String> list = new ArrayList<>(data);
results.values = list;
results.count = list.size();
} else {
final ArrayList<String> list = new ArrayList<>(data);
final ArrayList<String> nlist = new ArrayList<>();
for (int i = 0 ; i < list.size(); i++) {
String item = list.get(i);
if (item.contains(prefix)) {
nlist.add(item);
}
}
results.values = nlist;
results.count = nlist.size();
}
return results;
}
#SuppressWarnings("unchecked")
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
notifyItemRangeRemoved(1, getItemCount()-1);
filteredData.clear();
filteredData.addAll((List<String>)results.values);
for(int i = 1; i < getItemCount() - 1; i++){
notifyItemInserted(i);
}
}
}
}
I'm not sure how correct this way is, but in my code I implemented it like that
private var headerList: List<HeaderItem> = listOf(HeaderItem("Title"))
private fun searchItem(items: List<Items>, query: String) {
items.filterIsInstance<MainItem>().filter { filteredItems ->
filteredItems.header.lowercase().contains(query.lowercase())
}.let { searchedItems ->
rvAdapter.submitList(headerList + searchedItems)
}
}
This way I was able to preserve header element when I did my search
I created a basic program in order to see how to make javaexe run;
The program has to be a windows service and should display a icon on the taskbar, when one click in the menu item, a messageBox is displayed.
But it does not run, especially the icon is not displayed.
Do you know why?
here are my files:
the service:
package service;
/**
* Created by User on 26/10/2014.
*/
public class Exemple_ServiceManagement {
static Corps app=null;
public static boolean serviceInit (){
app=new Corps();
return true;
}
public static void serviceFinish (){
app.setEnd(true);
}
public static String[] serviceGetInfo (){
return new String[]{"mon exemple","test","pas auto",
"1"};
}
}
the core part:
public class Corps extends Thread{
public boolean isEnd() {
return isEnd;
}
public void setEnd(boolean isEnd) {
this.isEnd = isEnd;
}
public boolean isEnd=false;
/*******************************************/
public Corps()
{
start();
}
/*******************************************/
public void run(){
while (!isEnd){
try {
Thread.sleep(250);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
and the taskbar part:
public class Exemple_TaskbarManagement {
public static void taskInit() {
}
public static String[][] taskGetMenu(boolean isRightClick, int menuID) {
return new String[][]
{
{"1", "test" , "", ""},
};
}
public static void taskDoAction (boolean isRightClick, int menuID){
if (!isRightClick && menuID==1){
javax.swing.JOptionPane.showMessageDialog(null,"Menu cliqué");
}
}
public static String[] taskGetInfo (){
return new String[]
{
"JavaExe : mon exemple",
"",
"",
"",
""
};
}
}
finally, the output directory contains:
- the file "Exemple.exe" (the javaexe exe)
- the file "Exemple.jar", generated from the above sources, without manifest
- the file "Exemple.properties", here is it:
JREversion =
PersonalClasspath =
MainArgs =
MainClass =
PersonalOptions =
RunAsService =
RunType =1
ClassDirectory =
ResourceDirectory =
URL_InstallJRE =
Display_BoxInstall =
PathBrowser =
PathJRE =
my question is very simple : do you know what's going wrong?
thanks
olivier
ps : I had a look at the example files but I want to make a basic project, not take an other from somebody else, in order to understand what I do.
Hi I'm trying to retrieve a linkedhashset from the Google datastore but nothing seems to happen. I want to display the results in a Grid using GWT on a page. I have put system.out.println() in all the classes to see where I go wrong but it only shows one and I don't recieve any errors. I use 6 classes 2 in the server package(ContactDAOJdo/ContactServiceImpl) and 4 in the client package(ContactService/ContactServiceAsync/ContactListDelegate/ContactListGui). I hope someone can explain why this isn't worken and point me in the right direction.
public class ContactDAOJdo implements ContactDAO {
#SuppressWarnings("unchecked")
#Override
public LinkedHashSet<Contact> listContacts() {
PersistenceManager pm = PmfSingleton.get().getPersistenceManager();
String query = "select from " + Contact.class.getName();
System.out.print("ContactDAOJdo: ");
return (LinkedHashSet<Contact>) pm.newQuery(query).execute();
}
}
public class ContactServiceImpl extends RemoteServiceServlet implements ContactService{
private static final long serialVersionUID = 1L;
private ContactDAO contactDAO = new ContactDAOJdo() {
#Override
public LinkedHashSet<Contact> listContacts() {
LinkedHashSet<Contact> contacts = contactDAO.listContacts();
System.out.println("service imp "+contacts);
return contacts;
}
}
#RemoteServiceRelativePath("contact")
public interface ContactService extends RemoteService {
LinkedHashSet<Contact> listContacts();
}
public interface ContactServiceAsync {
void listContacts(AsyncCallback<LinkedHashSet <Contact>> callback);
}
public class ListContactDelegate {
private ContactServiceAsync contactService = GWT.create(ContactService.class);
ListContactGUI gui;
void listContacts(){
contactService.listContacts(new AsyncCallback<LinkedHashSet<Contact>> () {
public void onFailure(Throwable caught) {
gui.service_eventListContactenFailed(caught);
System.out.println("delegate "+caught);
}
public void onSuccess(LinkedHashSet<Contact> result) {
gui.service_eventListRetrievedFromService(result);
System.out.println("delegate "+result);
}
});
}
}
public class ListContactGUI {
protected Grid contactlijst;
protected ListContactDelegate listContactService;
private Label status;
public void init() {
status = new Label();
contactlijst = new Grid();
contactlijst.setVisible(false);
status.setText("Contact list is being retrieved");
placeWidgets();
}
public void service_eventListRetrievedFromService(LinkedHashSet<Contact> result){
System.out.println("1 service eventListRetreivedFromService "+result);
status.setText("Retrieved contactlist list");
contactlijst.setVisible(true);
this.contactlijst.clear();
this.contactlijst.resizeRows(1 + result.size());
int row = 1;
this.contactlijst.setWidget(0, 0, new Label ("Voornaam"));
this.contactlijst.setWidget(0, 1, new Label ("Achternaam"));
for(Contact contact: result) {
this.contactlijst.setWidget(row, 0, new Label (contact.getVoornaam()));
this.contactlijst.setWidget(row, 1, new Label (contact.getVoornaam()));
row++;
System.out.println("voornaam: "+contact.getVoornaam());
}
System.out.println("2 service eventListRetreivedFromService "+result);
}
public void placeWidgets() {
System.out.println("placewidget inside listcontactgui" + contactlijst);
RootPanel.get("status").add(status);
RootPanel.get("contactlijst").add(contactlijst);
}
public void service_eventListContactenFailed(Throwable caught) {
status.setText("Unable to retrieve contact list from database.");
}
}
It could be the query returns a lazy list. Which means not all values are in the list at the moment the list is send to the client. I used a trick to just call size() on the list (not sure how I got to that solution, but seems to work):
public LinkedHashSet<Contact> listContacts() {
final PersistenceManager pm = PmfSingleton.get().getPersistenceManager();
try {
final LinkedHashSet<Contact> contacts =
(LinkedHashSet<Contact>) pm.newQuery(Contact.class).execute();
contacts.size(); // this triggers to get all values.
return contacts;
} finally {
pm.close();
}
}
But I'm not sure if this is the best practice...