Posts by jinglylime

Thanks guys, that so much simpler.

Hi guys,
I wrote some code for finding the three longest words in a string. The code I wrote seem too complicated, is there a better way to appoarch this?

public class Size {
    public String[] threeLongest(String word){
        String[] three = new String[3];
        String[] words = word.split(" ");
        three[0] = longest(word);
        three[1] = find(words, three[0]);
        three[2] = find(words, three[0], three[1]);
        return three;
    }

    public String longest(String word){
        String[] words = word.split(" ");
        int largestLength = -1;
        String largestWord ="";

        for(String x:words)
            if(x.length()>=largestLength){
                largestWord = x;
                largestLength = x.length();
            }   
        return largestWord;
    }

    private String find(String[] words, String longest){
        String l1 ="";
        int lnum = -1;
        for(String x: words){
            if(!x.equals(longest)){
                if(x.length()>= lnum){
                        l1=x;
                        lnum=x.length();
                }   
            }   
        }
        return l1;
    }

    private String find(String[] words, String l1, String l2){
        String longest ="";
        int lnum = -1;
        for(String x: words){
            if(!x.equals(l1)){
                if(!x.equals(l2))
                    if(x.length()>= lnum){
                            longest=x;
                            lnum=x.length();
                    }   
            }   
        }
        return longest;
    }
}

I kinda understand what you are saying.So I did this but it only shows one shape and not all of it. Sorry, I've just started learning opengl.

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <GL/glut.h>
#include <windows.h>


int frame=0;

void myinit(void)
{
    int i;
    //glEnable(GL_BLEND);
    glClearColor(1.0, 1.0, 1.0, 0.0); /* white background */
    /* set up viewing */
    glColor3f(0.0,0.0,0.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(-120.0, 120.0, -120.0, 120.0);
}

void display(void)
{
    glClear(GL_COLOR_BUFFER_BIT);
    /* define a point data type */
        typedef GLfloat point2[2];
    point2 vertices[4]={{20,20},{20,-20},{-20,-20},{-20,20}}; // A square

        glColor3f(((float)rand())/RAND_MAX, ((float)rand())/RAND_MAX,((float)rand())/RAND_MAX); // Random color

        glBegin(GL_LINE_LOOP);
            glVertex2f(vertices[0][0],vertices[0][1]);
            glVertex2f(vertices[1][0],vertices[1][1]);
            glVertex2f(vertices[2][0],vertices[2][1]);
            glVertex2f(vertices[3][0],vertices[3][1]);
        glEnd();

        glRotatef(9,0,0, 1);
        glScalef(1.09,1.09,1);

    glutSwapBuffers();
}

void animationFunc(void){
    if(frame++<=30){
        Sleep(1000);
    }
    glutPostRedisplay();
}

int main(int argc, char** argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB); /* default, not needed */
    glutInitWindowSize(500,500); /* 650 x 650 pixel window */
    glutInitWindowPosition(100,100); /* place window top left on display */
    glutCreateWindow("Images"); /* window title */
    srand(time(NULL));
        myinit(); /* set attributes */
    glutDisplayFunc(display);/* display callback invoked when window opened */
    glutIdleFunc(animationFunc);
    glutMainLoop(); /* enter event loop */
}

Thanks Emil, I've tried using the glutIdleFunc function. The animation works, but when it gets to the end its start flicking. Is is how i've used the glutSwapBuffers?

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <GL/glut.h>
#include <windows.h>

int frame=0;

void myinit(void)
{
    int i;
    //glEnable(GL_BLEND);
    glClearColor(1.0, 1.0, 1.0, 0.0); /* white background */
    /* set up viewing */
    glColor3f(0.0,0.0,0.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(-120.0, 120.0, -120.0, 120.0);
}

void clear(void)
{glClear(GL_COLOR_BUFFER_BIT);  /*clear the window */}



void AnimateImg1(void)
{
    /* define a point data type */
        typedef GLfloat point2[2];
    point2 vertices[4]={{20,20},{20,-20},{-20,-20},{-20,20}}; // A square

    if(frame++<=30)
        {
        glMatrixMode(GL_MODELVIEW);
        glColor3f(((float)rand())/RAND_MAX, ((float)rand())/RAND_MAX,((float)rand())/RAND_MAX); // Random color
        glBegin(GL_LINE_LOOP);
                glVertex2f(vertices[0][0],vertices[0][1]);
                glVertex2f(vertices[1][0],vertices[1][1]);
                glVertex2f(vertices[2][0],vertices[2][1]);
                glVertex2f(vertices[3][0],vertices[3][1]);
            glEnd();
        glRotatef(9,0,0, 1);
        glScalef(1.09,1.09,1);
        glMatrixMode(GL_PROJECTION);
        glutSwapBuffers();
        Sleep(1000);
    }
    glutSwapBuffers();
    glFlush();
}

void display( void )
{
    glClear(GL_COLOR_BUFFER_BIT);  /*clear the window */
    frame=0;
    glutIdleFunc(AnimateImg1);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    frame=0;
 }

int main(int argc, char** argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB); /* default, not needed */
    glutInitWindowSize(500,500); /* 650 x 650 pixel window */
    glutInitWindowPosition(100,100); /* place window top left on display */
    glutCreateWindow("Images"); /* window title */
    glutDisplayFunc(display);/* display callback invoked when window opened */
    srand(time(NULL));
        myinit(); /* set attributes */

    glutMainLoop(); /* enter event loop */
}

Hi,I have encountered a problem while doing the animation for my program. I wanted keep adding a another shape on top of another. But for evry second image the background changes to black. Can you point out what I've done wrong. Thanks.

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <GL/glut.h>
#include <windows.h>



void myinit(void)
{
    //glEnable(GL_BLEND);
    glClearColor(1.0, 1.0, 1.0, 0.0); /* white background */
    /* set up viewing */
    glColor3f(0.0,0.0,0.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(-110.0, 110.0, -110.0, 110.0);
}

void display( void )
{
    glutSwapBuffers();
        glFlush(); /* clear buffers */
}


void displayAnim( void )
{
    glLoadIdentity();
    glClear(GL_COLOR_BUFFER_BIT);  /*clear the window */
    int i = 0;
    /* define a point data type */
        typedef GLfloat point2[2];
    point2 vertices[4]={{20,20},{20,-20},{-20,-20},{-20,20}}; // A square

    glMatrixMode(GL_MODELVIEW);
    for(i=1;i<=30;i++)
            {
        glMatrixMode(GL_MODELVIEW);
        glColor3f(((float)rand())/RAND_MAX, ((float)rand())/RAND_MAX,((float)rand())/RAND_MAX); // Random color
        glBegin(GL_LINE_LOOP);
                glVertex2f(vertices[0][0],vertices[0][1]);
                glVertex2f(vertices[1][0],vertices[1][1]);
                glVertex2f(vertices[2][0],vertices[2][1]);
                glVertex2f(vertices[3][0],vertices[3][1]);
            glEnd();
        glRotatef(9,0,0, 1);
        glScalef(1.09,1.09,1);
        glMatrixMode(GL_PROJECTION);
        glutSwapBuffers();
        Sleep(500);
        }
    glMatrixMode(GL_PROJECTION);
    glutSwapBuffers();
        glFlush(); /* clear buffers */
 }

void displayNoAnim( void )
{
    glLoadIdentity();
    glClear(GL_COLOR_BUFFER_BIT);  /*clear the window */
    int i = 0;
    /* define a point data type */

        typedef GLfloat point2[2];
    point2 vertices[4]={{20,20},{20,-20},{-20,-20},{-20,20}}; // A square

    glMatrixMode(GL_MODELVIEW);
    for(i=1;i<=30;i++)
            {
        glColor3f(((float)rand())/RAND_MAX, ((float)rand())/RAND_MAX,((float)rand())/RAND_MAX); // Random color
        glBegin(GL_LINE_LOOP);
                glVertex2f(vertices[0][0],vertices[0][1]);
                glVertex2f(vertices[1][0],vertices[1][1]);
                glVertex2f(vertices[2][0],vertices[2][1]);
                glVertex2f(vertices[3][0],vertices[3][1]);
            glEnd();
        glRotatef(9,0,0, 1);
        glScalef(1.09,1.09,1);
        }
    glMatrixMode(GL_PROJECTION);
    glutSwapBuffers();
        glFlush(); /* clear buffers */
 }

void popupmenu(int id)
{
    glMatrixMode(GL_MODELVIEW);
    if(id==3){
        exit(0);
    }
    else if(id==2){
        displayNoAnim();
    }
    else if(id==1){
        displayAnim();
    }
}

int main(int argc, char** argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB); /* default, not needed */
    glutInitWindowSize(500,500); /* 650 x 650 pixel window */
    glutInitWindowPosition(100,100); /* place window top left on display */
    glutCreateWindow("Images"); /* window title */
    glutDisplayFunc(display);/* display callback invoked when window opened */
    srand(time(NULL));
        myinit(); /* set attributes */
    glutCreateMenu(popupmenu);
    glutAddMenuEntry("animated display mode",1);
    glutAddMenuEntry("non-animated display mode",2);
    glutAddMenuEntry("exit",3);
    glutAttachMenu(GLUT_RIGHT_BUTTON);
    glutMainLoop(); /* enter event loop */
    return 1;
}

Hi, I'm having trouble with setting up my table. How do i get the header to show initially. I want "code", "Number" and "Value" as the header. And I want to know if the way i added the table is correct? Can you help me please. Thank you!

import model.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import java.util.*;

public class Shares extends JPanel
{
    private JButton btnFind = new JButton();
    private JTextField txtId = new JTextField(10);
    private JTable tableShare = new JTable();
    Customers customers = null;
    
    public Shares(Trader trader)
    {
        customers = trader.customers();
        setup();
        build();
    }
    
    private void setup()
    {
        setLayout(new FlowLayout());
        setBorder(BorderFactory.createLineBorder(Color.blue));
    }
    
    private void build()
    {
        Box box1 = Box.createHorizontalBox();
        box1.add(new JLabel("Your id"));
        box1.add(txtId);
        btnFind.setText("Find");
        box1.add(btnFind);
        Box box2 = Box.createVerticalBox();
        box2.add(box1);
        box2.add(Box.createVerticalStrut(20));
        setTable();
        box2.add(tableShare);
        add(box2);
        setBtnFind();
    }
    
    private void setBtnFind()
    {
        btnFind.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                btnFindActionPerformed(evt);
            }
        });
    }
    
    private void btnFindActionPerformed(java.awt.event.ActionEvent evt){       
        Customer customer = customer();
        LinkedList<Share> shares= customer.shares();
        int j =0;
        for(Share share: shares){       
            tableShare.setValueAt(share.code(), j, 0);
            tableShare.setValueAt(share.number()+"", j, 1);
            tableShare.setValueAt(share.cost()+"", j, 2);
            j++;
        }   
    }
    
    private Customer customer(){
        int custId = Integer.parseInt(txtId.getText());
        Customer customer = customers.customer(custId);
        return customer;
    }
    
    private void setTable(){
        tableShare.setModel(new DefaultTableModel(
            new String[][]{
                {null, null, null},
                {null, null, null},
                {null, null, null},
                {null, null, null},
                {null, null, null},
                {null, null, null},
                {null, null, null},
            },
            new String[]{
                "Code","Number","Value"
            }
        ));
    }
}

oh thanks. i get it now. =D

Hi how do you delete the input on the textfield after a button is pressed. Thanks

Hi I'm new to GUI. Ive created a calculator but i dont know how to get the number from the textfield and calculate the answer. Can u suggest ways i can do this. Thankyou.

Hi, I need to write a system that simulates buying and selling on the stock market with just text outputs. I need to create a menu so the user can register and delete thier account. Also be able to buy and sell shares.

So far I have my classes and attibuttes

public class User
{
    private int Id;
    private String name;
    private double trade;
}

public class Share
{
    private String code;
    private int quantity;
    private double price;
}

public class Trade 
{
    private LinkedList<Share> shares = new LinkedList<Share>();
    private LinkedList<User> users = new LinkedList<User>();
}

My plan is to create the users and shares in the Trade class, and write the methods for register, delete, sell and buy in the trade class as well. I will then call these methods in a Menu class.

I'm not sure if this is the right appoarch in writing this program. Can you guys help me if my classes and attributes are right thanks.

Yes, Thankyou.

I realise it prints all the cards in a line.

Thanks, I made a silly mistake

Hi, I need to write a pontoon game. So far i wrote the Deck and Card classes. When i try to print the toString in my deck class i get "Deck@6612fc02". What i wanted is to print 13 cards on each row. May you help me thanks.

public class Deck
{
    private LinkedList<Card> card = new LinkedList <Card>();
    private Iterator <Card> it;
    private char[] suit = {'H','D','C','S'};

    
    public Deck()
    {
        for(int i = 0; i< 4; i++) 
        {
            for(int j = 1; j <= 13; j++)
                card.add(new Card(j,suit[i]));                             
        }  
    }
    
    public void show()
    {
        System.out.println(toString());
    }

    
    public String toSring()
    {
        String s = " ";
        
        for(int i =0; i < 13; i++)    
        {
            s = card.toString() + "\n";
        }        
        return s;
    }
    
}

public class Card
{
    private int value;
    private char suit;
    
    public Card(int value, char suit)
    {
        this.value = value;
        this.suit = suit;
    }
    
    public String toString()
    {
        String s= suit + " " + value;
        return s;
    }
}

Thanks guys, it helped alot.

Thanks i've solved that. I still have problem with

Rectangle biggest = findBiggest();

i get an error "findBiggest(Rectangle[]) in BiggestRectangleProgram cannot be applied to ()" Thanks

Hi I've fixed it but still having problems with the line Rectangle biggest = findBiggest();, and the line return Rectangle[]; in readRectangles() method. Can you help me please. thanks

import javax.swing.*;
import java.util.*;

public class BiggestRectangleProgram
{
    private static final Scanner keyboard = new Scanner(System.in);
    
    public static void main(String[] args)
    {
        Rectangle[] rects = readRectangles();
        Rectangle biggest = findBiggest();
                                System.out.println("The biggest rectangle is " + biggest);
    }

    private static Rectangle findBiggest(Rectangle[] rects)
    {
        Rectangle biggestSoFar = rects[0];
        for (int i = 1; i < rects.length; i++)
        {
            //if (this one is bigger than biggestSoFar)
            if(rects[i].getArea() > biggestSoFar.getArea())
            //    biggestSoFar = this one
                biggestSoFar = rects[i];
        }
        return biggestSoFar;
    }

    private static Rectangle[] readRectangles()
    {
        // This method contains both syntax errors *and* logic errors
        //
        int howMany = getInt("How many rectangles?");
        Rectangle[] rects = new Rectangle[howMany];
        for (int i = 0; i < rects.length; i++)
        {
            int width = getInt("Width of rectangle #"+i+":");
            int height = getInt("Height of rectangle #"+i+":");
            rects[i] = new Rectangle(width, height);
        }
        return Rectangle[]; // problem here
    }

    private static int getInt(String prompt)
    {
        System.out.print(prompt + " ");
                                return keyboard.nextInt();
    }
}

Hi guys, Im trying to write a program that find the biggest rectangle by its area. I've tried and it doesnt seem to compile. Can you help me please, thanks.

public class Rectangle
{
    private int width;
    private int height;

    public Rectangle(int width, int height)
    {
        this.width = width;
        this.height = height;
    }

    // How big is this rectangle?
    public int getArea()
    {
        return width * height;
    }

    public void setWidth(int width)
    {
        this.width = width;
    }

    public int getWidth()
    {
        return width;
    }

    public void setHeight(int height)
    {
        this.height = height;
    }

    public int getHeight()
    {
        return height;
    }

    public String toString()
    {
        return width + "x" + height;
    }
}

import javax.swing.*;
import java.util.*;

public class BiggestRectangleProgram
{
    private static final Scanner keyboard = new Scanner(System.in);
    
    public static void main(String[] args)
    {
        Rectangle[] rects = readRectangles();
        Rectangle[] biggest = findBiggest();
                                System.out.println("The biggest rectangle is " + biggest);
    }

    private static Rectangle findBiggest(Rectangle[] rects)
    {
        Rectangle biggestSoFar = rects[0];
        for (int i = 1; i < rects.length; i++)
        {
            //if (this one is bigger than biggestSoFar)
            if(rects[i] > biggestSoFar)
            //    biggestSoFar = this one
                biggestSoFar = rects[i];
        }
        return biggestSoFar;
    }

    private static Rectangle[] readRectangles()
    {
        // This method contains both syntax errors *and* logic errors
        //
        int howMany = getInt("How many rectangles?");
        Rectangle[] rects = new Rectangle();
        for (int i = 0; i < rects[i]; i++)
        {
            int width = getInt("Width of rectangle #"+i+":");
            int height = getInt("Height of rectangle #"+i+":");
            rects[i] = new Rectangle(width, height);
        }
        return Rectangle();
    }

    private static int getInt(String prompt)
    {
        System.out.print(prompt + " ");
                                return keyboard.nextInt();
    }
}

hi, im trying to make a bike move by using the pedal() method, the method will move the bike forward a distance of half the circumference of a wheel. ive tried creating the pedal() method however when the method is invoke the position of the bike is still the same. please help me. thanks.

import java.lang.Math;

public class Wheel
{
    private double position;
    private double radius;

    public Wheel()
    {
        position = 0.0;
        radius = 50.0;
    }

    public void setRadius(double newRadius)
    {
        radius = newRadius;
    }
    
    public void setPosition(double newPosition)
    {
        position = newPosition;
    }

    public void rollForward(double distance)
    {
        position = position + distance;
    }

    public double getPosition()
    {
        return position;
    }
    
    public double getRadius()
    {
        return radius;
    }
    
    public double getCircumference()
    {
        double circumference;
        circumference = 2*radius*Math.PI;
        return circumference;
    }
     
}

public class Bike
{
    private Wheel frontWheel;
    private Wheel backWheel;

    public Bike()
    {
        
        frontWheel = new Wheel();
        backWheel = new Wheel();
        
        frontWheel.setPosition(50);
        backWheel.setPosition(-50);
    }
    
    public double getPosition()
    {
        double position;
        position = (frontWheel.getPosition() + backWheel.getPosition())/2;
        return position;
    }
    public double pedal() // here's my problem
    {
        
        double position;
        position = getPosition() + frontWheel.getCircumference()/2;
        return position;
    }
}