Prime Check Algorithm
In abstract algebra, objects that behave in a generalized manner like prime numbers include prime components and prime ideals. A prime number (or a prime) is a natural number greater than 1 that is not a merchandise of two smaller natural numbers. method that are restricted to specific number forms include Pépin's test for Fermat numbers (1877), Proth's theorem (c. 1878), the Lucas – Lehmer primality test (originated 1856), and the generalized Lucas primality test.
package Maths;
import java.util.Scanner;
public class PrimeCheck {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter a number: ");
int n = scanner.nextInt();
if (isPrime(n)) {
System.out.println(n + " is a prime number");
} else {
System.out.println(n + " is not a prime number");
}
scanner.close();
}
/***
* Checks if a number is prime or not
* @param n the number
* @return {@code true} if {@code n} is prime
*/
public static boolean isPrime(int n) {
if (n == 2) {
return true;
}
if (n < 2 || n % 2 == 0) {
return false;
}
for (int i = 3, limit = (int) Math.sqrt(n); i <= limit; i += 2) {
if (n % i == 0) {
return false;
}
}
return true;
}
}
