IT and Technology Articles

Implement a Java method that finds two neighbouring numbers in an array with the smallest distance to each other.

2013-01-05T13:20:00.001-08:00

Implement a Java function that finds two neighbouring numbers in an array with the smallest distance to each other. The function should return the index of the first number.

In the sequence 4 8 6 1 2 9 4 the minimum distance is 1 (between 1 and 2). The function should return the index 3 (of number 1).

class LangFund3{
    static void smallestDistance(int [] array){

        int smallest = Math.abs(array[0]-array[1]);
        int index = 0;
        for(int i=1; i<array.length-1; i++){
            int value = Math.abs(array[i]-array[i+1]);
            if(value< smallest){
            smallest= value;
            index = i;
            }

        }
        System.out.println(smallest);
        System.out.println(index);

    }
    public static void main(String [] args){
        int []arr= new int[]{4,8,6,1,2,9,4};
        smallestDistance(arr);
    }
}

How to find the largest and smallest number from a given Array using Java?

2013-01-05T12:56:00.003-08:00

Find the largest and smallest number from a given array.

This java example shows how to find the largest and smallest number in an array.

        public class FindLargestSmallestNumber {

            public static void main(String[] args) {

                    //array of 10 numbers
                    int numbers[] = new int[]{32,43,53,54,32,65,63,98,43,23};

                    //assign first element of an array to largest and smallest
                    int smallest = numbers[0];
                    int largetst = numbers[0];

                    for(int i=1; i< numbers.length; i++)
                    {
                            if(numbers[i] > largetst)
                                    largetst = numbers[i];
                            else if (numbers[i] < smallest)
                                    smallest = numbers[i];

                    }

                    System.out.println("Largest Number is : " + largetst);
                    System.out.println("Smallest Number is : " + smallest);
            }
    }

NumberFormatException and Exception hierarchy.

2013-01-05T11:29:00.001-08:00

NumberFormatException and Exception hierarchy.
When we catch an exception with catch clause, we should catch exception from narrow to wide. Otherwise compiler will give a compilation error.
Here is a simple example to illustrate the NumberFormatException and usage of Exception hierarchy.

class NumberFormat{
    void throwExcep(){
        String s=null;
        int [] val={1,2,3,4,5};
        String ss="ABCD";

        try{
        int i=Integer.parseInt(ss);
        }
        catch(NumberFormatException np){
            System.out.println("NumberFormat");

        }
        catch(ArrayIndexOutOfBoundsException ae){
            System.out.println("ArrayIndexOutOfBounds");
        }
        catch(Exception e){
            System.out.println("Exception");
        }

    }
    public static void main(String args[]){
        NumberFormat nf= new NumberFormat();
        nf.throwExcep();
    }
}

How to through and catch a NullPointerException in Java?

2013-01-05T11:07:00.000-08:00

Simple example to show how to through and catch a NullPointerException in Java.

class NullPointer{
    public static void main(String args[]){
        String s=null;

            try{
                System.out.println(s.length());
            }
            catch(NullPointerException e){
                System.out.println("Null Pointer Exception caught by code");
            }
    }
}

How to validate a Social Security Number(SSN) using Java.

2013-01-05T11:00:00.000-08:00

How to validate a SSN Number using Java?

SSNValidator class.

import java.util.regex.*;
class SSNValidator{
    public static void isValidSSN(String ssn) throws Exception{

        //Initialize reg expression for SSN.
        String expression = "^\\d{3}[- ]\\d{2}[- ]\\d{4}$";
        CharSequence inputStr = ssn;
        Pattern pattern = Pattern.compile(expression);
        Matcher matcher = pattern.matcher(inputStr);

            if(matcher.matches()){
            System.out.println("Correct SNN Number");
            }
            else{
                throw new MyException(ssn);
            }
    }
    public static void main(String args[])throws Exception{
                String cmd="";
                try{
                    cmd=args[0];
                    }
                    catch(ArrayIndexOutOfBoundsException ae){
                    System.out.println("You shoud input your SSN number");
                    }
                isValidSSN(cmd);
    }
}

Creating my own Exception class by extending Exception class.

class MyException extends Exception{
    private String s="";
    MyException(String val){
        this.s=val;

    }
    public String toString(){
        return "SSN number you were enter" + " " +s+" is not valid. "+ "please try again with correct format as given here. Ex:123-44-5678";
    }

}

How to run?

Copy both java sources into one folder.
Open cmd and navigate to that folder.
Compile main class(SSNValidator).
Then run with the SSN number. Ex(java SSNValidator 123-67-7890).

Meaning of Regex expression:

"^\\d{3}[- ]\\d{2}[- ]\\d{4}$";

    ^\\d{3}: Starts with three numeric digits.
      [- ]: Followed by an "-"
      \\d{2}: Two numeric digits after the "-"
      [- ]: contain an second "-" character.
       \\d{4}: ends with four numeric digits.

Above Regex format accepts only following format "xxx-xx-xxxx".

If you would like to change the Regex expression to accept 9 digits regardless of above format.

String expression = "^\\d{3}[- ]?\\d{2}[- ]?\\d{4}$";

This expression can accept the format given below.

SSN format xxx-xx-xxxx, xxxxxxxxx, xxx-xxxxxx; xxxxx-xxxx:

     ^\\d{3}: Starts with three numeric digits.
    [- ]?: Followed by an optional "-"
    \\d{2}: Two numeric digits after the optional "-"
    [- ]?: May contain an optional second "-" character.
    \\d{4}: ends with four numeric digits.

In java, How to print reversely in a given String?

2012-10-07T19:07:00.002-07:00

In java, How to print reversely in a given String?

class ReveseString{
public static void main(String args[]){
String s="String is immutable";
for(int i=s.length()-1; i>=0; i--){
System.out.print(s.charAt(i));
}
}
}

How to write a program in java to display given certain pattern?

2012-10-07T18:57:00.000-07:00

How to write a program in java to display given certain pattern?

1
12
123
1234
12345

class Example5{
public static void main(String args[]){
for(int i=1;i<6;i++){
System.out.println();
for(int j=1; j<=i; j++){
System.out.print(j);
}
}
}
}

How to Extend the Volume/Size of the C drive in Windows 7?

2012-10-05T09:55:00.001-07:00

How to Extend the Volume/Size of the C drive in Windows 7?

1.Right click on my computer and select manage

2.Next Click Storage< Disk Management
You will be see something similar to this image.

3.You sould have free space near to C drive. for example if you have D drive adjacent to C drive. You should backup the data of D drive to another Drive and need to be delete the D drive.

4.Then Right click on C drive. you can see "extend voulme" option in the panel. If your "extend volume" option disable in that panel that means you don't have adjacent drive with free sapce. So you should do the step 3.

5. After that You will be asked for how much amount you need to allocate for the C drive. Select the Directions as what you want. Finally you have done.

How to Disable Back button in android

2012-01-03T22:55:00.000-08:00

/**
* To disable back button(when click back button nothing happen)
*/
@Override
public void onBackPressed() {
return;
}

How to Launch Activities from different application in android

2012-01-03T22:47:00.000-08:00

For Example We have two application with same package and Different Namespace.

First Application: Com.Example.Application1

Second Application: Com.Example.Application2

In this case you can define common Manifest file for both Application1 and Application2 as given below

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="Com.Example">

And add given line to your manifest file

<activity android:name=".Application2/Activity2">
  <intent-filter>
    <action android:name="Application2.intent.action.Launch" />
    <category android:name="android.intent.category.DEFAULT" />
  </intent-filter>
</activity>

Now you can create an Intent to launch Activity2 from the Activity1 with this line of code:

Intent intent = new Intent("Application2.intent.action.Launch");

startActivity(intent);

how to use android emulator to find the gps location.

2011-12-09T23:40:00.001-08:00

Usually from your emulator you can't get current location when you run your GPS location finder application.

First you have to make sure this line of code is available in your source code.

// Register the listener with the Location Manager to receive location updates
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);

You can also request location updates from both the GPS and the Network Location Provider by calling requestLocationUpdates() twice—once for NETWORK_PROVIDER and once for GPS_PROVIDER. But when you run the applicatin in emulator, you should use GPS provider to obtain your location.

And now you have to move to below location by yourself. And run the ddms.bat file

C:/android sdk/tools/ddms.bat

When you run this bat file you will find an emulator controller tab there. from this tab you can pass locations to emulator by longitude and latitude of your current location.

Here you can find your location's longitude and latitude.

http://www.satsig.net/maps/lat-long-finder.htm

Difference between GPS and Android's Network Location Provider to acquire the user location

2011-12-09T21:58:00.001-08:00

Obtaining User Location in android application using GPS or Network Location Provider

GPS	Android's Network Location Provider
Although GPS is most accurate	Android's Network Location Provider determines user location using cell tower and Wi-Fi signals
It only works outdoors	Providing location information in a way that works indoors and outdoors
It quickly consumes battery power	Uses less battery power
It doesn’t return the location as quickly as users want.	Responds faster

Note: To obtain the user location in your application, you can use both GPS and the Network Location Provider, or just one.

How to redirect to another window in android when button click

2011-12-08T22:09:00.001-08:00

This Sample Code explain how to show another window of given url when button click in android.

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainWindowActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Button button = (Button)findViewById(R.id.button1);    

    button.setOnClickListener(new OnClickListener() {
      public void onClick(View arg) {
        Intent viewIntent =
          new Intent("android.intent.action.VIEW",
            Uri.parse("https://google.com"));
          startActivity(viewIntent);
      }
    });
}
}

How to Create HelloAndroid or Your First Android Application

2011-12-07T22:09:00.001-08:00

First thing you have to set up the Environment to run the Android application. If you don't done so far. you can follow this link to setup your Android SDK.
http://agileswaran.blogspot.com/2011/12/simple-and-easy-way-to-install-android.html

Open eclipse
After that go to File<New<Other

It's open another window then Select Android Folder<Android Project

Then Specify your project Name, Build Target and Application Info

After give all details click finish to create your Android project.
Open your src folder<java class

In first Example I explain about layout set by . XML class this is located under res<layout folder in your project.

So you can easily add buttons, textview, image, etc via XML layout.

import android.app.Activity;
import android.os.Bundle;
public class HelloWorld extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
}
}

Second Example, I explain about layout set by programming.
Display the "Hello,Android" via programming.

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class HelloAndroid extends Activity {
 /** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    TextView tv = new TextView(this);
    tv.setText("Hello, Android");
    setContentView(tv);
 }

Finally simply hit F11 to build and run the your project.

How to show another activity in android when button click

2011-12-07T21:45:00.001-08:00

Using Intent in an Android application to show another activity

In my Android application, I have two activity classes FirstActivity and Second Activity. I have a button on the first one and I want to show the second when it is clicked.

public class FirstActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);  
Button firstButton = (Button)findViewById(R.id.first); 

firstButton.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View view) {
    Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
    startActivity(intent);
  }
});
}
}
The second class that should show when the button is clicked:

 public class SecondActivity extends Activity {

 @Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.second);
Button secondButton = (Button) findViewById(R.id.second);

secondButton.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View view) {
    finish();
  }
});
}
}

Important: add this line to your AndroidManifest.xml:

 <activity android:name=".SecondAcitivty" />

Simple and Easy way to Install Android SDK

2011-12-02T23:03:00.000-08:00

How to Installing the Android SDK in two minutes

System Requirements

System and software requirements for developing Android applications using the Android SDK

Supported Operating Systems

· Windows XP (32-bit), Vista (32- or 64-bit), or Windows 7 (32- or 64-bit)

· Mac OS X 10.5.8 or later (x86 only)

· Linux (tested on Ubuntu Linux, Lucid Lynx)

Supported Development Environments

Eclipse IDE

· Eclipse 3.5 (Galileo) or greater

· JDK 5 or JDK 6 (JRE alone is not sufficient)

If you don’t have already installed Eclipse, you can download it from this location: http://www.eclipse.org/downloads/

Step1: Downloading the SDK Starter Package

Get the latest version of the SDK starter package from the SDK download page.

If you downloaded a .zip or .tgz package (instead of the SDK installer), unpack it to a safe location on your machine. By default, the SDK files are unpacked into a directory named android-sdk-<machine-platform>.

If you downloaded the Windows installer (.exe file), run it now and it will check whether the proper Java SE Development Kit (JDK) is installed, then install the SDK Tools into a default location.

Note: After finished the sdk installer, Android SDK manager ask you to download and install the recommended packages. If you don’t trick the check box. Then you can manually do it in step 3.

Given Screenshot is taken after installing Recommended Components for android SDK.
In this Screen shot I have installed only recommended components except Android API 3.0.

Screenshot 1:

Step2: Installing the ADT Plugin for Eclipse
You must have a compatible version of Eclipse installed on your development computer
When your Eclipse and Android SDK environments are ready, continue with the ADT installation as described in the steps below
Downloading the ADT Plugin

1. Start Eclipse, then select Help > Install New Software....

2. Click Add, in the top-right corner.

3. In the Add Repository dialog that appears, enter "ADT Plugin" for the Name and the following URL for the Location:

https://dl-ssl.google.com/android/eclipse/

4. Click OK

Note: If you have trouble acquiring the plug-in, try using "http" in the Location URL, instead of "https" (https is preferred for security reasons).

5. In the Available Software dialog, select the checkbox next to Developer Tools and click Next.

6. In the next window, you'll see a list of the tools to be downloaded. Click Next.

7. Read and accept the license agreements, then click Finish.

Note: If you get a security warning saying that the authenticity or validity of the software can't be established, click OK.

8. When the installation completes, restart Eclipse.

Configuring the ADT Plug-in

After you've successfully downloaded the ADT as described above, the next step is to modify your ADT preferences in Eclipse to point to the Android SDK directory:

1. Select Window > Preferences... to open the Preferences panel (Mac OS X: Eclipse > Preferences).

2. Select Android from the left panel.

You may see a dialog asking whether you want to send usage statistics to Google. If so, make your choice and click Proceed. You cannot continue with this procedure until you click Proceed.

3. For the SDK Location in the main panel, click Browse... and locate your downloaded SDK directory.

4. Click Apply, and then OK.

Done! If you haven't encountered any problems, then the installation is complete. If you're installing the Android SDK for the first time, return to Installing the SDK to complete your setup.

Step 3: Adding Platforms and Other Components

You can launch the Android SDK and AVD Manager in one of the following ways:

· From within Eclipse, select Window > Android SDK and AVD Manager.

· On Windows, double-click the SDK Manager.exe file at the root of the Android SDK directory.

· On Mac or Linux, open a terminal and navigate to the tools/ directory in the Android SDK, then execute:

·        android

To download components, use the graphical UI of the Android SDK and AVD Manager to browse the SDK repository and select new or updated components

Recommended Components

The SDK repository contains a range of components that you can download. Use the table below to determine which components you need, based on whether you want to set up a basic, recommended, or full development environment:

Screenshot 1: display the all the components available to download and install.

Environment	SDK Component
Basic	SDK Tools
	SDK Platform-tools
	SDK platform
+
Recommended (plus Basic)	Documentation
	Samples
	Usb Driver
+
Full (plus Recommended)	Google APIs
	Additional SDK Platforms

If you have successfully installed android sdk. You can navigate to File>New>other>Android folder.
You have any problems to install Android SDK on your computer. Let me know

How to read input from console in Java

2011-11-24T03:19:00.001-08:00

How to read input from console -Java

There are two common ways to read input from console.

1) InputStreamReader wrapped in a BufferedReader
2) Scanner classes in JDK1.5

First we look up on InputStreamReader , BufferedReader example

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class ReadConsoleSystemInput {
public static void main(String[] args) {

System.out.println("Enter something here to Read : ");

try{
BufferedReader bufferRead = new BufferedReader(new InputStreamReader(System.in));
String s = bufferRead.readLine();

System.out.println(s);
}
catch(IOException e)
{
e.printStackTrace();
}

}
}

Another way is using Scanner class

import java.util.Scanner;

public class ReadConsoleScannerInput {
public static void main(String[] args) {

System.out.println("Enter something here to Read : ");

String s;

Scanner In = new Scanner(System.in);
s = In.nextLine();

In.close();
System.out.println(s);
}
}

How to detect/match the words start with Uppercase letter in a given paragraph

2011-11-24T03:07:00.001-08:00

Problem:
How to detect/match the word start with uppercase letter in a given paragraph. Write a program to accept three line of input as console input and display the words start with Uppercase letter only.
Example Input:
This Is very funny thing
My First coding is helloworld in java
Example is given for easy understand

Out Put:
This Is
My First
Example

Solution in java

import java.io.*;
import java.util.regex.*;
import java.util.Scanner;
public class problem9 {

public static void main(String[] args) {
String line1,line2,line3;
Scanner in = new Scanner(System.in);
String pattern = "(?U)\\b\\p{Lu}\\p{L}*\\b"; // match the words start with uppercase

line1 = in.nextLine();
line2 = in.nextLine();
line3 = in.nextLine();
String delimiter = "\\s"; //space delimiter
String[] words1 = line1.split(delimiter);
String[] words2 = line2.split(delimiter);
String[] words3 = line3.split(delimiter);

System.out.println();
for(int i=0; i<words1.length;i++){
if(words1[i].matches(pattern)){
System.out.println(words1[i]);
}
}

for(int i=0; i<words2.length;i++){
if(words2[i].matches(pattern)){
System.out.println(words2[i]);
}
}

for(int i=0; i<words3.length;i++){
if(words3[i].matches(pattern)){
System.out.println(words3[i]);
}
}
}
}

Java program to print numbers from some range except the number end with some digit

2011-11-23T03:21:00.001-08:00

Write a program to print numbers from 258 to 393 except the number end with 5.
output should be like this:
258
259
260
261
262
263
264
266
...
and so on

Solution to the above problem

class problem2{
public static void main(String args[]){

for(int i=258; i<394;i++){

String aString = Integer.toString(i);
char aChar = aString.charAt(2);
String s1 = Character.toString(aChar);
int n = Integer.parseInt(s1);
if(n!= 5){
System.out.println(aString);
}
}
}
}

Working with java String.split() method

2011-11-22T00:54:00.001-08:00

PROBLEM

Ross is an event organizer. He has received data regarding the participation of employees in two different events. Some employees have participated in only one event and others have participated in both events. Ross now needs to count the number of employees who have taken part in both events. The records received by Ross consist of employee ids, which are unique. Write a program that accepts the employee ids participating in each event (the first line relates to the first event and the second line relates to the second event). The program should print the number of common employee ids in both the events.

Suppose the following input is given to the program, where each line represents a different event:

1001,1002,1003,1004,1005

1106,1008,1005,1003,1016,1017,1112

Now the common employee ids are 1003 and 1005, so the program should give the output as:

Solution via Simple java code

import java.util.Scanner;

class problem3{

public static void compare(String id1[],String id2[]){

int k=0;

for(int i=0;i<id1.length; i++){

int x = Integer.parseInt(id1[i]);

for(int j=0; j<id2.length; j++){

int y = Integer.parseInt(id2[j]);

if(x==y){

k++;

}

System.out.println(k);

}

public static void main(String args[]){

String firstLine;

String secondLine;

Scanner in = new Scanner(System.in);

firstLine = in.nextLine();

secondLine = in.nextLine();

String delimiter = "\\,";

String[] array1 = firstLine.split(delimiter); // array1{1001,1002,1003,1004,1005};

String[] array2 = secondLine.split(delimiter); // array2{1106,1008,1005,1003,1016,1017,1112};

compare(array1, array2);

}

Note: Input given via Console input(using scanner class).
After run this code via command prompt, you can type values and then enter. now you can see the output.

Calculating the distance travelled by a car at different time intervals

2011-11-22T00:35:00.001-08:00

PROBLEM
Write a program to calculate the distance travelled by a car at different time intervals. The initial velocity of the car is 36 km/hr and the constant acceleration is 5 m/s2.

The formula to calculate distance is:

Distance Travelled = u*t+((a*t*t)/2) where,
u = initial velocity of the car (36 km/hr)
a = acceleration of the car (5 m/s2)
t = time duration in seconds

The program should accept 2 time intervals as the input (one time interval per line) and print the distance travelled in meters by the car (one output per line).

Definitions:
————
1 kilometer = 1000 meters
1 hour = 3600 seconds

Let us suppose following are the inputs supplied to the program

10
8

Then the output of the program will be

350
240

Solution in simple java code

import java.util.Scanner;
class problem4{
public static void calculateDistance(int t1,int t2){
int u = 10; // in m/s
int a = 5; // in m/s2
int distanceTravel1 = u*t1+((a*t1*t1)/2);
int distanceTravel2 = u*t2+((a*t2*t2)/2);
System.err.println(distanceTravel1);
System.err.println(distanceTravel2);
}
public static void main(String args[]){
int firstValue;
int secondValue;
Scanner in = new Scanner(System.in);
firstValue = in.nextInt();
secondValue = in.nextInt();
calculateDistance(firstValue,secondValue);
}
}

Note: Input given via Console input(using scanner class).
After run this code via command prompt, you should type two values (one value per line) and then enter. now you can see the output.

How to print a pyramid of numbers in Java

2011-11-18T23:09:00.001-08:00

Write a program which will print the below structures according to the input provided to the program. The program should accept 3 inputs in the form of numbers between 1 and 9, both inclusive (one number per line) and then generate the corresponding structures based on the input.

Suppose the following sequence of numbers is supplied to the program:
3
2
4

Then the output should be:

Solution to above problem

import java.util.Scanner;
class problem7{
public static void main(String args[]){
 int a,b,c;
 Scanner in = new Scanner(System.in);
 a = in.nextInt();
 b = in.nextInt();
 c = in.nextInt();
 int[] array={a,b,c};
    int k;
  for(int x=0; x<3; x++){
  int y = array[x];
  int z= y+1;
   for(int i=1;i<=y;i++){                    
   System.out.println();
   System.out.format("%"+z+"s", ""); 
    
    for(int j=1;j<=i;j++)
    {
    k=i;
    System.out.format("%"+1+"s", ""); 
    System.out.print(k);  
    }
    z--;
   }
  }
   }
}

Validating usernames in Java

2011-11-18T22:41:00.001-08:00

Sam wants to select a username in order to register on a website.
The rules for selecting a username are:

1. The minimum length of the username must be 5 characters and the maximum may be 10.
2. It should contain at least one letter from A-Z
3. It should contain at least one digit from 0-9
4. It should contain at least one character from amongst @#*=
5. It should not contain any spaces

Write a program which accepts 4 usernames (one username per line) as input and checks whether each of them satisfy the above mentioned conditions.
If a username satisfies the conditions, the program should print PASS (in uppercase)
If a username fails the conditions, the program should print FAIL (in uppercase)

Suppose the following usernames are supplied to the program:
1234@a
ABC3a#@
1Ac@
ABC 3a#@

Then the output should be:
PASS
PASS
FAIL
FAIL

Solution to above problem:
import java.util.regex.*;
import java.util.Scanner;
public class problem5 {

public static void main(String[] args) {
String[] Array = new String[4];
Scanner in = new Scanner(System.in);
String pattern = "((?=.*[0-9])(?=.*[A-Z])(?=.*[@#*=])(?=[\\S]+$).{5,10})";

for(int i=0; i<Array.length;i++){
Array[i] = in.nextLine();
}
System.out.println(""); //print empty line

for(int i=0; i<Array.length;i++){
if(Array[i].matches(pattern)){
System.out.println("PASS");
}
else {
System.out.println("FAIL");
}
}
in.close();

}
}

frog hops problem

2011-11-18T22:36:00.001-08:00

Kermit, a frog hops in a particular way such that:

1. He hops 20cm in the first hop, 10cm in the second hop and 5cm in the third hop.
2. After three hops Kermit rests for a while and then again follows the same hopping pattern.

Calculate the total distance travelled by Kermit (in centimeters) for the provided number of hops. Exactly 4 numbers of hops will be provided to the program (one number per line) as per the below example.

Suppose the following number of hops is provided to the program:

4
6
3
5

Then the total distance covered should be displayed as follows:

55
70
35
65

Solution to Above Problem:

import java.util.Scanner;
public class problem1 {

public static void main(String[] args) {
int a,b,c,d;
Scanner in = new Scanner(System.in);
a = in.nextInt();
b = in.nextInt();
c = in.nextInt();
d = in.nextInt();
int[] array = {a,b,c,d};
int k = 0;

for(int i=0; i<array.length; i++){
int n = array[i];
int x = n/3;
int y = n%3;
int z = x*35;

switch(y){
case 0: k = 0 + z; break;
case 1: k = 20 + z; break;
case 2: k = 30 + z; break;
case 3: k = 35 + z; break;
}
System.out.println(k);
}
}
}

Java Conversion (From X type to Y type)

2011-11-18T22:12:00.001-08:00

integer to String :
int i = 20;
String str = Integer.toString(i);
or
String str = "" + i

double to String :
String str = Double.toString(i);

long to String :
String str = Long.toString(l);

float to String :
String str = Float.toString(f);

String to integer :
str = "50";
int i = Integer.parseInt(str);
or
int i = Integer.valueOf(str).intValue();

String to double :
Double d = Double.valueOf(str).doubleValue();

String to long :
long l = Long.valueOf(str).longValue();
or
Long l = Long.parseLong(str);

String to float :
Float f = Float.valueOf(str).floatValue();

char to String:
String s = String.valueOf('c');

decimal to binary :
int i = 42;
String bin = Integer.toBinaryString(i);

decimal to hexadecimal :
int i = 42;
String hexstr = Integer.toString(i, 16);
or
String hexstr = Integer.toHexString(i);
or
(with leading zeroes and uppercase)
public class Hex {
public static void main(String args[]){
int i = 42;
System.out.print
(Integer.toHexString( 0x10000 | i).substring(1).toUpperCase());
}
}

hexadecimal (String) to integer :
int i = Integer.valueOf("B8DA3", 16).intValue();
or
int i = Integer.parseInt("B8DA3", 16);

integer to ASCII code (byte):
char c = 'A';
int i = (int) c; // i = 65 DECIMAL

To extract Ascii codes from a String
String test = "ABCD";
for ( int i = 0; i < test.length(); ++i ) {
char c = test.charAt( i );
int j = (int) c;
System.out.println(j);

}

Note :To catch illegal number conversion, use the try/catch clause
Example to use try catch clause
try{
i = Integer.parseInt(aString);
}
catch(NumberFormatException e) {
.........
}