Big Integer advanced operations

              Big integer is a special integer which holds the larger value than primitive data types like int or long. Basic operations on big int is explained in part1.

In this blog post, it includes the advanced operations like GCD, prime number generation, modular arithmetic and primality testing.

GCD:

Greatest common divisor(It gives you  the largest positive integer that can divide two or more integers without remainder)

Prime number generation:

Prime number is a natural number which can be divided by itself and by 1.

Modular arithmetic:

It is modulus operation which gives you the remainder.

Primality testing:

              It is an algorithm to determine the input is prime.

Here is the program.

import java.math.BigInteger;

public class advancebigIntEg {

public static void main(String[] args) {

BigInteger x = new BigInteger("345216723456123457");

BigInteger y = new BigInteger("897645324123412345");

// Let us calculate GCD

BigInteger gcdcalc = x.gcd(y);

System.out.println("The GCD value is: " + gcdcalc);

// It is the next prime number generation coe

BigInteger nextPrimeno = x.nextProbablePrime();

System.out.println("Next prime number is: " + nextPrimeno);

//Modulus operation

BigInteger modvalue = x.mod(y);

System.out.println("Modulus value is: " + modvalue);

// Primality testing code is given here

boolean primeNo = x.isProbablePrime(1);

if (primeNo == true)

System.out.println("It is a prime number");

else

System.out.println("It is not a prime number");

}

}

The output is given below.

C:\raji\blog>javac advancebigIntEg.java

C:\raji\blog>java advancebigIntEg

The GCD value is: 1

Next prime number is: 345216723456123473

Modulus value is: 345216723456123457

It is not a prime number

Note : Big integer is always  take time compared to primitive data types. But it suitable for complex number operations on large numbers. So choose it wisely according to your applications.