Eclipse Versions

Eclipse Versions

Factorial Example in Java

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

public class FactorialEx {


public static void main(String[] args) throws NumberFormatException,
IOException {

InputStreamReader input = new InputStreamReader(System.in);
BufferedReader bu = new BufferedReader(input);
System.out.println("Enter Integer value:");
int n = Integer.parseInt(bu.readLine());
int fact = 1;
for (int i = n; i >= 1; i--) {
fact = fact * i;
}
System.out.println("Factorial of " + n + " is : " + fact);
}

}

/*

Output:

Enter Integer value:

5

Factorial of 5 is : 120

*/

To find the first repeated character in a string

Example: 
java

The repeated character in java is : a

public class FirstRepeatedCharacter {

/**
* @param args
*/
public static void main(String[] args) {


String str ="welcome";

for(int i=0;i<=str.length()-1;i++){
int count = 0;
for(int j=i+1;j<str.length();j++){

if( str.charAt(i) == str.charAt(j)){
count= count + 1;
break;
}
}
if(count != 0){
System.out.println("The first repeated character in a welcome is : " + str.charAt(i));
break;
}
}
}

}

/*
Output:
The first repeated character in a welcome  is: e
*/

Find the first non repeated character in a string

To find the first non repeated character in a string

Example:  madam

The non repeated character in madam is : d

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

public class NonRepeatCharacter {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub


InputStreamReader input = new InputStreamReader(System.in);
BufferedReader br  = new BufferedReader(input);

System.out.println("Enter String value :");
String str = br.readLine();

for(int i=0;i<str.length();i++){
int count = 0;
for(int j=0;j<str.length();j++){

if(i!=j && str.charAt(i) == str.charAt(j)){
count = count +1 ;
break;
}
}
if(count == 0){
System.out.println("The first non repeated character is : " +str.charAt(i));
break;
}
}

}

}

/*
Output:

Enter String value :
character
The first non repeated character is : h

*/

Floyd's Triangle Examples

/*
1. Example:
1
01
101
0101

*/


public class FloydsTriangle{

/**
* @param args
*/
public static void main(String[] args) {

for(int i=1;i<5;i++){
for(int j=1;j<=i;j++){


if( i == j){
System.out.print("1");
} else if( (i+j)%2 == 0){
System.out.print("1");
}else{
System.out.print("0");
}
}
System.out.println(" ");

}

}

}

/*

Output:

1
01
101
0101

*/

---------------------------------------------------------------------------------------------------
2.Example :


1
22
333
4444
55555
55555
4444
333
22
1

public class FloydsTriangle2{

/**
 * @param args
 */
public static void main(String[] args) {

for(int i=1;i<=5;i++){

for(int j=1;j<=i;j++){

System.out.print(i);

}

System.out.println("");

}

for(int i=5;i>0;i--){

for(int j=1;j<=i;j++){

System.out.print(i);

}

System.out.println("");

}

}

}

---------------------------------------------------------------------------------------------------------

3.Example

1 

22 

333 

4444 

55555 

public class FloydsTriangle2{

/**
 * @param args
 */
public static void main(String[] args) {

for(int i=1;i<=5;i++){

for(int j=1;j<=i;j++){

System.out.print(i);

}

System.out.println(" ");

}

}

}

--------------------------------------------------------------------------------------
4. Example


1
12
123
1234
12345

for(int i=1;i<=5;i++){

for(int j=1;j<=i;j++){

System.out.print(j);

}

System.out.println(" ");

}

----------------------------------------------------------------------------------------------

Check the given number is Armstrong number are not ?

An Armstrong number is a Three digit number such that the sum of the cubes of its digit is equal to the number itself

Ex : 153 as 153= 1+ 125+27 which 1^3+5^3+3^3

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

public class Armstrong {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub

InputStreamReader reader = new InputStreamReader(System.in);

BufferedReader br = new BufferedReader(reader);

System.out.println("Enter n value :");

String st = br.readLine();

int n = Integer.parseInt(st);
int n1 = n;

int sum = 0;
while(n>0){

int r = n%10;
sum = sum+(r*r*r);
n =n/10;

}
if(n1 == sum){
System.out.println("The given number is Armstrong  number");
}else{
System.out.println("The given number is not Armstrong  number");
}
}

}

/*Output :

Enter n value :
153
 The given number is Armstrong  number
------------------------------------------------------
Enter n value :
235
The given number is not Armstrong  number



*/

Fibonacci Series Example

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

public class FibonacciSeries {

/**
* @param args
* @throws IOException
* @throws NumberFormatException
*/
public static void main(String[] args) throws NumberFormatException, IOException {


InputStreamReader reader = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(reader);
System.out.println("Enter n value:");
int n = Integer.parseInt(br.readLine());
int a;
int b=0;
int c=1;

for(int i=1 ; i<=n ; i++){
System.out.print(b + "  ");
a = b;
b = c;
c = a+b;

}
}
}

/*
Output:


Enter n value:
10
0  1  1  2  3  5  8  13  21  34

*/

Swapping of two numbers without using temporary variable

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

public class Swapping {

/**
* @param args
* @throws IOException
* @throws NumberFormatException
*/
public static void main(String[] args) throws NumberFormatException, IOException {

InputStreamReader reader = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(reader);


System.out.println("Enter a and b values");
int a = Integer.parseInt(br.readLine());
int b = Integer.parseInt(br.readLine());

System.out.println( "Before Swapping : A value =  " + a + " B value =" + b);

/*without temporary variable*/
a = a + b;
b = a - b;
a = a - b;
System.out.println( "After swapping: A value = " + a + " B value =" + b);

}

}


/*

Output:
Enter a and b values
12
43
Before Swapping : A value =  12 B value =43
After swapping: A value = 43 B value =12
*/

Swap two numbers using a temporary variable


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

public class Swapping {

/**
* @param args
* @throws IOException
* @throws NumberFormatException
*/
public static void main(String[] args) throws NumberFormatException, IOException {

InputStreamReader reader = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(reader);


System.out.println("Enter a and b values");
int a = Integer.parseInt(br.readLine());
int b = Integer.parseInt(br.readLine());

System.out.println( "Before Swapping : A value =  " + a + " B value =" + b);

int temp;
temp = a;
a = b;
b= temp;

System.out.println( "After swapping: A value = " + a + " B value =" + b);


}


}


/*Output:
Enter a and b values
12
43
Before Swapping : A value =  12 B value =43
After swapping: A value = 43 B value =12
*/

To Check given Number Palindrome or not

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

public class Palindrome {

/**
* @param args
* @throws IOException
* @throws NumberFormatException
*/
public static void main(String[] args) throws NumberFormatException, IOException {
// TODO Auto-generated method stub

InputStreamReader input = new InputStreamReader(System.in);

BufferedReader bu = new BufferedReader(input);
System.out.println("Enter n value ");
int n = Integer.parseInt(bu.readLine());
int y =n;

int temp = 0;
int sum = 0;

while(n > 0){
temp = n%10;
sum = sum*10 + temp;

             n = n/10;

}

System.out.println("rever number  " + sum);
if(sum == y ){

System.out.println("The given number is palindrome");
}else{
System.out.println("The given number is not palindrome");
}

}

}

Reverse String Word Example

1. Reverse String Word Example
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class ReverseStringWord {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub


InputStreamReader reader = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(reader);

System.out.println("Enter the string ");
String str = br.readLine();
System.out.println(str);

String str1[] = str.split(" ");

for(int i=str1.length-1; i>=0;i--){

System.out.print(str1[i].toString() + " ");
}
}

}