/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package XXXX;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.StringTokenizer;
/**
*
* @author poochedi
*/
public class LongestIncreasingSubsequence {
public static void main(String[] args) throws IOException {
InputStreamReader iReader = new InputStreamReader(System.in);
BufferedReader bReader = new BufferedReader(iReader);
ArrayList seqList = new ArrayList();
ArrayList lngIncSeq = new ArrayList();
System.out.println("Enter a sequence of numbers seperated by space Hit enter to terminate");
String seqString = bReader.readLine();
if(seqString != null) {
StringTokenizer tokenizer = new StringTokenizer(seqString);
while(tokenizer.hasMoreTokens()) {
seqList.add(tokenizer.nextToken());
}
System.out.println("seqList " + seqList.toString());
}
else
System.out.println("No sequence");
//Now that I have the list I can find the increasing subseq
Iterator seqItr = seqList.iterator();
//add the 1st to the result list
int first = Integer.parseInt((String)seqItr.next());
lngIncSeq.add(first);
System.out.println("lngIncSeq - 1st elem " + lngIncSeq.toString());
while(seqItr.hasNext()) { //every element is looked O(n)
int next = Integer.parseInt((String) seqItr.next()); //access is O(1)
if(lngIncSeq.size() < 2) {
System.out.println("next " + next + " first " + first );
if (next < first) {
//the new number is lesser than the already existing in the list
lngIncSeq.remove(0);
lngIncSeq.add(next);
first = next;
//lngIncSeq.set(0, next);
System.out.println("lngIncSeq if next < first " + lngIncSeq.toString() );
}
else if(next > first) {
//append the new number to the already existing list
lngIncSeq.add(next);
}
}
else {
//now that the result list is more than 2 in length see how the next num is w.r.to prev two numbers in the list
int prev = (int) (lngIncSeq.get(lngIncSeq.size()-2)); //O(1)
int pres = (int) (lngIncSeq.get(lngIncSeq.size()-1)); //O(1)
if(next > pres && next > prev) {
//add next to end of the list
lngIncSeq.add(next); //O(n) added to end of the list
}
else if( next > prev && next < pres) {
int index = lngIncSeq.indexOf(pres);
lngIncSeq.remove(index); //O(n) removal from end of list
lngIncSeq.add(next); //O(n) addition to end of list
}
//if next is less than both pres and prev, ignore it => no change to the existing result list
}
}
System.out.println("lngIncSeq " + lngIncSeq.toString());
}
}
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/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package XXXX;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
/**
*
* @author poochedi
*/
public class CommonSubSequence {
static HashMap table = new HashMap();
public static void main(String[] args) throws IOException {
InputStreamReader iReader = new InputStreamReader(System.in);
BufferedReader bReader = new BufferedReader(iReader);
ArrayList seqA = new ArrayList();
ArrayList seqB = new ArrayList();
ArrayList lngIncSeq = new ArrayList();
System.out.println("Enter a sequence of numbers seperated by space Hit enter to terminate");
String seqString = bReader.readLine();
if(seqString != null) {
StringTokenizer tokenizer = new StringTokenizer(seqString);
while(tokenizer.hasMoreTokens()) {
seqA.add(tokenizer.nextToken());
}
System.out.println("seqList " + seqA.toString());
}
else
System.out.println("No sequence");
System.out.println("Enter a sequence of numbers seperated by space Hit enter to terminate");
seqString = bReader.readLine();
if(seqString != null) {
StringTokenizer tokenizer = new StringTokenizer(seqString);
while(tokenizer.hasMoreTokens()) {
seqB.add(tokenizer.nextToken());
}
System.out.println("seqList " + seqB.toString());
}
else
System.out.println("No sequence");
//compare seqA and seqB
if(seqA.size() < seqB.size()){
//enter elements of B to hashtable and compare them with the smaller list,seqA
fillTable(seqB);
compare(seqA);
}
else {
//seqA will get into hashtable and is compared with the smaller list seqB
fillTable(seqA);
compare(seqB);
}
}
public static void fillTable(ArrayList list) {
Iterator listItr = list.iterator();
while(listItr.hasNext()) {
table.put(Integer.parseInt(listItr.next().toString()), 0);
}
}
public static void compare(ArrayList list) {
int tableLookup = 0;
//for each element in the list lookup whether its in the list
//if so set the elements val = 1.
//finally print the elements in the table with val = 1. they are the elements common to both
Iterator listItr = list.iterator();
while(listItr.hasNext()) {
int elt = Integer.parseInt((String)(listItr.next()));
System.out.println("elt " + elt);
if(table.get(elt) != null) {
tableLookup = (int) table.get(elt);
table.put(elt, 1); //this elt matches
}
}
System.out.println("Printing the common elements");
//get the set of entries
Set set = table.entrySet();
//get an iterator
Iterator itr = set.iterator();
while(itr.hasNext()) {
Map.Entry elt = (Map.Entry)itr.next();
if(elt.getValue() == 1){
System.out.println(elt.getKey());
}
}
}
}
Given a string.Replace the words whose length>=4 and is even,with a space between the two equal halves of the word.consider only alphabets for finding the eveness of the word
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package XXXXX;
import java.util.StringTokenizer;
/**
*
* @author poochedi
*/
public class SplitStringHalves {
public static void main(String[] args) {
String input = “Hello How are youu eleven’s heartt”;
String output = “”;
StringTokenizer st = new StringTokenizer(input);
while(st.hasMoreTokens()) {
String string = st.nextToken();
if(string.length() >=4 && string.length()%2 == 0) {
System.out.println(“String qualified ” + string);
int spaceAfter = string.length() / 2; //determine space after how many chars
System.out.println(“Space needed ” + spaceAfter);
String stringPartA = string.substring(0,string.length()/2);
if(stringPartA.length() == spaceAfter)
stringPartA+=” “;
String stringPartB = string.substring(string.length()/2, string.length());
string = stringPartA + stringPartB;
System.out.println(“String ” + string);
}
output+=” ” + string;
}
System.out.println(“Input ” + input);
System.out.println(“Output ” + output);
}
}
You have a stream of numbers of unknown length. When you hit a zero, the stream is terminated. Return the largest even number and the largest odd number.
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package XXXX;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Collections;
import java.util.ArrayList;
/**This prog accepts input until user enters 0
* then find the largest odd and largest even number
*
* @author poochedi
*/
public class StreamOfNumbers {
public static void main(String[] args) throws IOException {
ArrayList oddList = new ArrayList();
ArrayList evenList = new ArrayList();
int maxOdd = 0;
int maxEven = 0;
System.out.println(“Enter the input. enter 0 to terminate”);
BufferedReader bReader = new BufferedReader(new InputStreamReader(System.in));
String input = bReader.readLine();
int inputNumber = Integer.parseInt(input);
while(inputNumber !=0) {
//classify this input number
if(inputNumber%2 == 0) {
//this number is even
evenList.add(inputNumber);
}
else {
oddList.add(inputNumber);
}
//accept more input
System.out.println(“Enter the input. enter 0 to terminate”);
input = bReader.readLine();
inputNumber = Integer.parseInt(input);
}
//user entered a 0 So terminate getting the input
//Now find the maximum of the odd number and max of even number
if(!oddList.isEmpty()){
maxOdd = (int) Collections.max(oddList);
System.out.println(” Max Odd ” + maxOdd);
}
else if(oddList.isEmpty())
System.out.println(“OddList empty”);
if(!evenList.isEmpty()) {
maxEven = (int) Collections.max(evenList);
System.out.println(” Max Even ” + maxEven);
}
else if(evenList.isEmpty())
System.out.println(“Even list empty”);
}
}
Hey Folks,
Playing with Java Swing for a quiet a month now. Its more interesting than I thought of. This article is about adding AtionListener to a JLabel. You think its useless? Well.. read on!
Its usual to associate an action with a JButton. Its click, when I click a button an action is performed. (Clicking Next button in an app, takes me to next JFrame). But there exists situations where you want to associate a ActionListener to JLabel. I encountered one such recently.
The scenario is, an imageIcon Label (A label with image painted on it) is added to a panel. When I single-click the icon (a JLabel actually) , the resize border appears on the icon, letting me to resize the icon. When I right-click the icon, a pop-up menu appears showing the option to Delete this icon. When I double-click the icon, it should take me to the next frame.
Lets leave the single-click and right-click. I am posting a simple example of
- Listening to double-click
- Associate an action with a JLabel double-click
- Frame Navigation, of course
There are 3 files
- LinkingFrames.java – Main class creates the parent JFrame. Has a label named NEXT. It takes me to next frame (Child Frame)
- ChildFrame.java – Has a label named BACK. Takes me back to parent frame
- MouseListenerHandler.java – Listens for mouse double-click and triggers the action corresponding to the frame you are in. (If u r in parent frame, u r taken to child and vice-versa)
CLASS : LinkingFrames.java
package linkingframes;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
/**
*
* @author poochedi
*/
public class LinkingFrames {
public static JFrame parent;
ChildFrame childframe;
public LinkingFrames(){
parent = new JFrame(“Parent Frame”);
parent.setName(“MY NAME IS CHILD”);
parent.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
parent.setSize(400,400);
parent.setVisible(true);
JLabel next = new JLabel(“NEXT”, JLabel.CENTER);
next.setToolTipText(“Double click to navigate”);
parent.add(next, BorderLayout.CENTER);
next.setName(“next”);
next.addMouseListener(new MouseListenerHandler());
//JButton nextButton = new JButton(“CLICK TO GO TO NEXT FRAME”);
//parent.add(nextButton, BorderLayout.CENTER);
//nextButton.addActionListener(new FrameActionHandler());
//nextButton.setActionCommand(“next”);
}
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
new LinkingFrames();
}
}
//================================================================================================================================================
CLASS : ChildFrame.java
package linkingframes;
import java.awt.BorderLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
/**
*
* @author poochedi
*/
public class ChildFrame {
public static JFrame child;
JButton backButton;
static boolean instanceExists = false;
public ChildFrame() {
child = new JFrame(“Child Frame”);
child.setName(“MY NAME IS CHILD”);
instanceExists = true;
// backButton = new JButton(“CLICK TO GO TO PARENT FRAME”);
// backButton.setActionCommand(“previous”);
// child.add(backButton, BorderLayout.CENTER);
child.setSize(600,500);
child.setVisible(true);
// backButton.addActionListener(new FrameActionHandler());
JLabel back = new JLabel(“BACK”, JLabel.CENTER);
back.setToolTipText(“Double click to navigate”);
child.add(back, BorderLayout.CENTER);
back.setLabelFor(backButton);
back.setName(“back”);
back.addMouseListener(new MouseListenerHandler());
}
}
//====================================================================================================================================================
CLASS : MouseListenerHandler.java
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package linkingframes;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
/**
*
* @author poochedi
*/
public class MouseListenerHandler implements MouseListener {
public MouseListenerHandler() {
}
@Override
public void mouseClicked(MouseEvent e) {
if(e.getClickCount() >=2) {
String actionName = e.getComponent().getName();
System.out.println(actionName);
if(actionName.equals(“next”)){
if(ChildFrame.instanceExists)
ChildFrame.child.setVisible(true);
else
new ChildFrame();
LinkingFrames.parent.setVisible(false);
}
else if(actionName.equals(“back”)) {
LinkingFrames.parent.setVisible(true);
ChildFrame.child.setVisible(false);
}
}
}
@Override
public void mousePressed(MouseEvent e) {
// throw new UnsupportedOperationException(“Not supported yet.”);
}
@Override
public void mouseReleased(MouseEvent e) {
// throw new UnsupportedOperationException(“Not supported yet.”);
}
@Override
public void mouseEntered(MouseEvent e) {
// throw new UnsupportedOperationException(“Not supported yet.”);
}
@Override
public void mouseExited(MouseEvent e) {
//throw new UnsupportedOperationException(“Not supported yet.”);
}
}
the code is self-explanatory. Hope u found it useful. Bye 🙂
Hey Folks,
This is all about the post
What: Object Interaction
Language: Java
Example Illustrated: CheckingBankAccount
Functionalities : Create, Credit, Debit, Display Bank accounts
DataStructure used : Hashtable ( To store and lookup accounts)
Constraints : Every debit made from an a/c with less than $100 will be charged $10 fee
Every debit made from an a/c with less than $0 balance will be charged $30 overdraft fee
How many classes : 3 (CheckingAccount.java, AccountTable.java, Tester.java)
Points to note :
CheckingAccount.java and AccountTable.java are defined in a PACKAGE checkingaccount
Data members of CheckingAccount.java don’t have any access-modifier (default modifier) . So it is visible for all classes in its own package . In other words, AccountTable.java can access it directly without using any get methods.
But, main class (Tester.java) is the one the user directly interacts with. User shouldn’t have access to the datamembers of bank account. In real world, a customer can credit or debit or view his own account details and not any body else. So giving access to the hashtable of accounts (AccountTable.java) is a very poor design and SHOULD BE AVOIDED.
Its for this reason, CheckingAccount and the data structure to hold it (AccounTable ) are in one package and they can access directly the datamembers of each other whereas to keep the user away, Tester.java is out of the checkingaccount package.
This way a user can interact with account classes only via accessors and mutators (get and set methods) and not directly with the data members of those classes. Now it makes sense why Tester was outside the package. If not, it can access the datamembers of other two classes directly.
As an example, thats why to access balance a datamember of CheckingAccount.java Tester.java uses account.getBalance() [an accessor – as datamember ‘balance’ cant be accessed directly outside the package ] and AccountTable.java uses account.balance as it is in the same package as CheckingAccount.java. The respective lines is made bold and Italicized in the code as well. Check it out below
Compilation :
1. Say you copy paste the Tester.java to a folder Bank
2. Create a folder checkingaccount inside Bank folder
3. Copy paste the remaining two java files to checkingaccount folder
Now, if u r under Linux OS, you may have something like
usr-name:~bank/ ls
Tester.java checkingaccount
usr-name:~bank/cd checkingaccount
usr-name:~bank/ checkingaccount/ ls
CheckingAccount.java AccountTable.java
Now give javac *.java (This creates class files for the above two java files)
Now cd .. and come to the parent directory (bank)
Now give javac Tester.java to create Tester.class
Now to execute the program give java Tester
So here is the code!
//Tester.java
/**
*
* @author poochedi
*/
import java.util.*;
import checkingaccount.*;
public class Tester {
public static void main(String[] args) {
System.out.println("Enter Your option (1-4) to continue and 5 to exit");
System.out.println("1.CREATE ACCOUNT 2.CREDIT 3.DEBIT 4.DISPLAY 5.EXIT" );
//create an object for hashtable
AccountTable table = new AccountTable();
Scanner scanObject = new Scanner(System.in);
Scanner scanDetails;
while( scanObject.hasNextLine() ) {
int option = scanObject.nextInt();
if(option > 5)
System.out.println("Enter a number from 1-5");
if(option == 1) {
//create an account
scanDetails = new Scanner(System.in);
System.out.println("Enter the following details");
System.out.println("Name");
String name = scanDetails.next();
System.out.println("A/c Number");
String acNumber = scanDetails.next();
CheckingAccount account = new CheckingAccount(name, acNumber);
//add the account to hash table
table.addAccount(account);
System.out.println("Account created successfully");
}
if(option == 2) {
//Credit to account
scanDetails = new Scanner(System.in);
System.out.println("Enter the name of the a/c holder");
String name = scanDetails.next();
CheckingAccount account = table.searchAccount(name);
if(account != null)
{
System.out.println("Enter the amount to be credited ");
double amount = Double.parseDouble(scanDetails.next());
account.credit(name, amount);
double newBalance = account.getBalance();
table.updateBalance(name,newBalance);
}
else
System.out.println("No such account found");
}
if(option == 3) {
//Debit from account
scanDetails = new Scanner(System.in);
System.out.println("Enter the name of the a/c holder");
String name = scanDetails.next();
CheckingAccount account = table.searchAccount(name);
if(account != null) {
System.out.println("Enter the amount to be debited ");
double amount = Double.parseDouble(scanDetails.next());
account.debit(amount);
//put into table the updated details
double newBalance = account.getBalance();
table.updateBalance(name,newBalance);
}
else
System.out.println("No such account found");
}
if(option == 4) {
//display account details
scanDetails = new Scanner(System.in);
System.out.println("Enter the name of the a/c holder");
table.displayAccount();
}
if(option == 5) {
System.out.println("Thanks for using our service");
System.exit(0);
}
System.out.println("Enter Your option (1-4) to continue and 5 to exit");
System.out.println("1.CREATE ACCOUNT 2.CREDIT 3.DEBIT 4.DISPLAY 5.EXIT");
scanObject = new Scanner(System.in);
}
}
}
===================================================================================================================
//AccountTable.java
package checkingaccount;
/**
*
* @author poochedi
*/
import java.util.*;
public class AccountTable {
//data member
//DEFAULT access modifier
//ACCESSIBLE ONLY WITHING THE PACKAGE
Hashtable <String, CheckingAccount> table;
//==========================================================================================================
public AccountTable() {
table = new Hashtable();
}
//==========================================================================================================
public void addAccount(CheckingAccount account) {
String key = account.accountHolder;
table.put(key, account);
}
//==========================================================================================================
public CheckingAccount searchAccount(String name) {
if(table.containsKey(name))
return table.get(name);
return null;
}
//==========================================================================================================
public void displayAccount() {
Enumeration enumObj = table.keys();
while(enumObj.hasMoreElements()) {
String acNumber = (String) enumObj.nextElement();
CheckingAccount acc = table.get(acNumber);
System.out.print(acc.accountHolder + " ");
System.out.print(acc.accountNumber + " ");
System.out.print(acc.overDraftCount + " ");
System.out.println(acc.balance + " ");
}
}
//==========================================================================================================
public void updateBalance(String name, double balance) {
if(table.containsKey(name)) {
CheckingAccount acc = table.get(name);
acc.balance = balance;
table.put(name, acc);
}
}
}
===================================================================================================================
//CheckingAccount.java
package checkingaccount;
/**
*
* @author poochedi
*/
public class CheckingAccount {
//data members -- DEFAULT access modifier
//So ACCESSIBLE ONLY WITHIN THE PACKAGE
String accountHolder;
String accountNumber;
double balance;
int overDraftCount;
//default constructor
public CheckingAccount() {
accountHolder = " ";
accountNumber = "0000000-000";
balance = 0.00;
overDraftCount = 0;
}
//parameterized constructor
public CheckingAccount(String acOwner, String acNumber) {
accountHolder = acOwner;
accountNumber = acNumber;
balance = 0.00;
overDraftCount = 0;
}
//==========================================================================================================
//mutators - set method - Process credit
//add amount to balance
public void credit(String name, double amountCredited) {
//Search the account
double totalOverDraftCharge = this.overDraftCount * 30;
this.balance = this.balance + amountCredited - totalOverDraftCharge;
}
//==========================================================================================================
//mutators - set method - Process debit
//deduct amount from balance
public void debit(double amountToDeduct) {
double charge = 0.00;
//if balance less than $100 deduct $10 for every check processed
if(this.balance < 100)
charge = 10.00;
this.balance = this.balance - amountToDeduct - charge;
if(this.balance < 0)
this.overDraftCount++;
}
//==========================================================================================================
//accessors - get methods - get the balance
public double getBalance() {
//Search the account
return this.balance;
}
}
I am yet another software engineer driven to America in search of better opportunities. Though onsite is one way to make it to USA, the land of opportunities, before you get one you are already tired of the routine mechanical work and are desperate to move to a better company. I din’t want to keep hopping from one company to another in search of a better work environment, which is non-existent! Though, engineers back in India, talk about how working in India is patriotic, they conveniently forget the fact that they too work for foreign clients. So there is no point in blaming those Indians settled in abroad as unpatriotic, for all of us work for USA.
Now, this may rise a question why should we work for some other nation when we have the strongest educated human resource. Well, we all study engineering because thats what fetches the highest salary now. From an IIT ian to a student from an average engineering college, every one dreams of a future in America. The impact of westernization is so high that gen-next kids listen only to Eminem and Justin Beiber and wonder at the awesomeness of English lyrics while we don’t consider lack of mother tongue knowledge as a shame anymore. Thats how we are wired! ok I am kind of drifting away from the intended topic.
Back to the question – What is happiness according to our generation, especially the IT sector? Even before I complete the question, anybody will answer MONEY! Kudos! U win the brownie points! This puts the next question – are we really happy by earning the money we dream? Answer may not be instant. How much ever time you pause or even if you go without answering, our conscience knows its a big NO!
Do you think those people who come to study Masters abroad are happy? Not atall! They slog to find part-time jobs. They earn a little, dream to save a lot, spend a little and look into the bank balance every time before they leave for grocery shopping. Well thats the way of student life in any foreign country.
Ok, now what about IT people in India. They earn pretty well. They should live life king-size. If thats what you think, I am sorry you are too naive! Money is an addiction. Its a craving. You always want more. IT people in India earn and invest in land or car or any thing for the sake of status. There starts the problem. Its indeed a wise idea to invest money. But even for a land in B’lore you need to invest all your savings. In addition to it, you will need a bank loan which will last for minimum 5 years. Awing at the mammoth loan, one works tirelessly, loosing interest in sex life and a happy family. Many of the IT folks don’t even have time to talk to their spouse because by the time they return home, they grow largely tired and need a sleep badly. This approach to life makes their spouse and kids desperate for warmth and care. This is the starting point for a cascade of problems in family life. People, especially women who realize this, want to leave their job and be at home attending their family. But any loan claimed, intimidates them and forces to understand, that only if both the adults go for job, the loan can be repaid else there is no end for it.
So what about IT people settled in USA and other foreign countries? They have green card, a regular working hours. They should be contented and happy. Unfortunately, answer is again a NO! Atleast, when you settle in India you have relatives (dad n mom) to help in case of any emergencies. Also, if you loose a job in one IT company, any day you can shift to some others easily. But in abroad, loosing your job is the last thing you want to think about! Starting from Auto Insurance to credit card bills, everything queues up, time and again and life becomes a bitter struggle. Not to mention about health care bills. If you are admitted for a mild chest pain, seeing the bill, you will either get a fatal heart attack or commit suicide! No kidding, even a X-ray costs $400 in USA. If you are in emergency ward for a severe stomach pain, on seeing the bill you are sure to develop chest pain, for, a half-an-hour time in emergency ward costs you $500. By the time you obtain green card, you could observe your hair line recedes, you put on weight out of stress and look 10+ of your actual age! Worst, is the dream to buy a home. Even if a husband and wife work, a mortgage per month costs 15 days salary of both. S0 what remains is, one month salary of one person, which tries to choke you before you could pay all other monthly bills.
Kaasu illadhavanuku oru prachana! irukuravanuku pala !!
Is it better to think that money is not happiness?? Folks, lets succumb to reality! We can’t do anything without money. Though not true, we are wired to think money is happiness. Hope you find enough happiness. Bye!
Welcome all!
This blog is all about my perceptions, learnings and struggles. I am yet another person dreaming of and working steadily towards a “secure” future! We may differ only in what we think security is!
poochedi 