## Friday, 6 December 2013

### Find GCD of two numbers in Java?

#### Code :

```/**
* Created with IntelliJ IDEA.
* User: aniket
* Date: 6/12/13
* Time: 4:46 PM
* To change this template use File | Settings | File Templates.
*/
public class GCDFinder {

public static int gcd(int a,int b){
int temp = a % b;
if(temp == 0)
return b;
else
return gcd(b,temp);
}

public static void main(String args[]){
System.out.println("GCD of 12 and 10 is : " + gcd(12,10));
}
}
```

#### Output :

GCD of 12 and 10 is : 2

Note : You can calculate LCM as Number1*Number2/GCD

### Find nth Fibonacci number in Java?

Fibonacci series is as follows

1 1 2 3 5 8 13 21 34...

Again for this we can have iterative approach as well as recursive. Recursive code is provided below

#### Recursive Code :

``` /**
* Created with IntelliJ IDEA.
* User: aniket
* Date: 6/12/13
* Time: 3:25 PM
* To change this template use File | Settings | File Templates.
*/
public class FibonacciFinder {

public static int fibonacci(int number){

if(number <= 2){
return 1;
}
else{
return  fibonacci(number - 1) + fibonacci(number - 2);
}
}

public static void main(String args[]){

System.out.println("8th fibonacci number is : " + fibonacci(8));

}

}
```

#### Output :

8th fibonacci number is : 21

#### Iterative Code :

```/**
* Created with IntelliJ IDEA.
* User: aniket
* Date: 6/12/13
* Time: 3:25 PM
* To change this template use File | Settings | File Templates.
*/
public class FibonacciFinder {
int prev = 1;
int curr = 1;
public int fibonacci(int number){

if(number < 2){
return curr;
}
else {
int temp;
for(int i = 0;i<number-2;i++){
temp = curr;
curr = curr + prev;
prev = temp;
}
return curr;
}
}

public static void main(String args[]){

System.out.println("8th fibonacci number is : " + (new FibonacciFinder()).fibonacci(8));
}

}
```

#### Output:

8th fibonacci number is : 21

### Find Power of a number in Java?

There are two ways to find power of a number. One is iterative which is very simple(Just multiply the number power number of times) and other is recursive. Following is the code to get power of a number in recursive way.

#### Code :

```/**
* Created with IntelliJ IDEA.
* User: aniket
* Date: 6/12/13
* Time: 3:08 PM
* To change this template use File | Settings | File Templates.
*/
public class PowerCalculator {

public static int pow(int base, int power){

if(power == 1){
return base;
}
if(power % 2 == 0){
return pow(base, power/2) * pow(base, power/2);
}
else {
return pow(base, power/2) * pow(base, power/2) + base;
}
}

public static void main(String args []){

System.out.println("4 raise to 2 : " + PowerCalculator.pow(4,2));

}

}
```

#### Output :

4 raise to 2 : 16

### Find factorial of a number in Java?

There are two ways to find factorial of a number. One is iterative which is very simple and other is recursive. Following is the code to get factorial by recursive method.

#### Code :

```/**
* Created with IntelliJ IDEA.
* User: aniket
* Date: 6/12/13
* Time: 2:52 PM
* To change this template use File | Settings | File Templates.
*/
public class FactorialFinder {

public static int factorial(int no){

if(no < 0){
throw new RuntimeException("Number cannot be Negative");
}
else if(no == 1){
return no;
}
else{
return no * factorial(no - 1);
}

}

public static void main(String args[]){
int number = 4;
System.out.printf("Factorial of 4 is : " + FactorialFinder.factorial(4));
}

}
```

#### Output

Factorial of 4 is : 24
t> UA-39527780-1 