Java

a[i] == 4
a[j] == 2

a[i] > a[j] 
=== 4 > 2 
=== true

for(int i=0; i< a.length ;i++) { // here i =0 then a[0]=4

           for(int j=i; j< a.length ;j++) { // here also j=i since i=0 then j=0 too,  a[0]= 4

i = 0
    j = 0    a[i] = 4; a[j] = 4
    j = 1    a[i] = 4; a[j] = 2    // <-- Your condition is met here
    j = 2    a[i] = 4; a[j] = 7

i = 1
    j = 1    a[i] = 2; a[j] = 2
    j = 2    a[i] = 2; a[j] = 7

i = 2
    j = 2    a[i] = 7; a[j] = 7

zarkerBlack wrote:

so I need an idea about math models

I already have done the work like this ,the real problem is about machine learning，how could the machine konw the way to the result,I have three ideas,one is let machine try all the ways,another is find the law,it like the deduction of mathematic，the last one is that,let machine think like man,it could do the work like a real person ,maybe i need to design a classifier like SVM to training the machie。
Do you have any advice about last two？

ArrayList<Book> bList = (ArrayList<Book>) oistr.readObject();
oistr.close();
for (Book bb : bList) {
    bb.skrivUt();
    // ta1.append("Titel " + b.getTitle() + "\n");
    // ta1.append("Författare: " + b.getAuthor() + "\n");
    // ta1.append("Pris: " + Integer.toString(b.getPrice()) + "\n");
    // ta1.append("\n");
    }//foreach

import javax.swing.BorderFactory;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JRadioButton;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.border.Border;
import javax.swing.border.EtchedBorder;


/*
import java.awt.BorderLayout;
import java.awt.Color;*/

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;

public class MainFrame extends JFrame implements ActionListener, MyContacts {
		
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	public JTextField txtFieldTitle;
	private JTextField txtFieldAuthor;
	private JTextField txtFieldPrice;
	private JTextField txtFieldLanguage;
	private JTextArea ta1;
	private JButton btn;
	private JButton btn2;
	private JButton btnClose;
	private JButton btnRemove;
	private JRadioButton proRadio;
	private JRadioButton amateurRadio;
	private ButtonGroup playersBtnGroup;
	private ArrayList<book> aList;
	//public ArrayList<programmingBook> ProgrammingList;
	private JLabel txtTextArea;
	private JLabel txtTitle;
	private JLabel txtAuthor;
	private JLabel txtPrice;
	private Border redBorder = BorderFactory.createLineBorder(Color.red);
	
	public MainFrame(){ //Construktor
	
		super("Library");
		
		setLayout(null);
	
		//Sätter storlek på fönstret.
		setSize(1200, 1000);
		
		//Hindra att fönstret kan ändras
		setResizable(false);
	
		
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	
		
		setVisible(true);
								 
		getContentPane().setBackground(Color.red);
		
		loadBook();
	
			
		//buttons
		btn = new JButton("Add book");
		btn.setBounds(120,70,200,20);
		add(btn);
		btn.addActionListener(this);
		
		btn2 = new JButton("Show books");
		btn2.setBounds(220,470,200,20);
		add(btn2);
		btn2.addActionListener(this); 
		
		btnClose = new JButton("Close");
		btnClose.setBounds(150,800,200,50);
		add(btnClose);
		btnClose.addActionListener(this); händelser
		
			
		
		//Textfields
		txtFieldTitle = new JTextField();
		txtFieldTitle.setBounds(570,70,200,20);
		add(txtFieldTitle);
		
		txtFieldAuthor = new JTextField();
		txtFieldAuthor.setBounds(570,110,200,20);
		add(txtFieldAuthor);
		
		txtFieldPrice = new JTextField();
		txtFieldPrice.setBounds(570,150,200,20);
		add(txtFieldPrice);
		
				
		
		//Textarea
		ta1 = new JTextArea();
		ta1.setBounds(720,470,400,420);
		ta1.setBorder(redBorder);
		add(ta1);
		
		
		
		//Labels
		txtTextArea = new JLabel("Böcker");
		txtTextArea.setBounds(720,430,200,20);
		add(txtTextArea);
		
		txtTitle = new JLabel("Titel");
		txtTitle.setBounds(500,70,200,20);
		add(txtTitle);
						
	}
	
public void actionPerformed(ActionEvent e) 	
{
				
	if(e.getSource() == btn) //add Book
	{
		String title = txtFieldTitle.getText();
	        String anAuthor = txtFieldAuthor.getText();
		String anPrice = txtFieldPrice.getText();
		String aLanguage = txtFieldLanguage.getText();
			
		int thePrice = Integer.parseInt(anPrice);
			
		book aBok = new book(title, anAuthor , thePrice);
		aList = new ArrayList<book>();
		aList.add(aBok);
	}//if source btn end
		
	if(e.getSource() == btn2) //Show books
	{
			for (book b : aList) {
		            ta1.append("Titel " + b.getTitle() + "\n");
		            ta1.append("Författare: " + b.getAuthor() + "\n");
		            ta1.append("Pris: " + Integer.toString(b.getPrice()) + "\n");
		            ta1.append("\n");
		         }
			
		}//if source btn2 end
		
		if(e.getSource() == btnClose)	//Close-button
		{
				saveBook(aList);
				System.exit(0);
		}
		
						
	}//ActionPerformed end
	
public void saveBook(ArrayList<book> aList)
{
    try
    {	
	FileOutputStream fil = new FileOutputStream("C:\\SavedObjects\\Objektfil.dat");
	ObjectOutputStream oostr = new ObjectOutputStream(fil);
	oostr.writeObject(aList);
	oostr.close();
    }
    catch (IOException e) 
    {
	System.out.println(e);
	System.out.println("Nu blev det visst fel i spara Bok");
    }
}//end saveBook	
	
@SuppressWarnings("unchecked")
public void loadBook()
{
	try
	{	
	   FileInputStream fil = new FileInputStream("C:\\SavedObjects\\Objektfil.dat");
	   ObjectInputStream oistr = new ObjectInputStream(fil);
	   aList = (ArrayList<book>) oistr.readObject();
	   oistr.close();
	}			
		
	catch (IOException e) 
	{
		System.out.println(e);
		System.out.println("Something went wrong in IO");
	}
		catch (ClassNotFoundException e)
		{
				System.out.println(e);
				System.out.println("Could not find class...");
		}
	}//end loadBook	
	
	
	
}

if(e.getSource() == btn) //add Book
{
    String title = txtFieldTitle.getText();
    // ...	
    book aBok = new book(title, anAuthor , thePrice);
    aList = new ArrayList<book>();
    aList.add(aBok);
}//if source btn end

larsp777 wrote:

Don't really know how to upgrade, could you tell me?

larsp777 wrote:

When I start the window it is blank or only a few items.

larsp777 wrote:

how can I upgrade your answer