39 lines
945 B
Java
39 lines
945 B
Java
package Maths;
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import java.util.Scanner;
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public class PrimeCheck {
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public static void main(String[] args) {
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Scanner scanner = new Scanner(System.in);
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System.out.print("Enter a number: ");
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int n = scanner.nextInt();
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if (isPrime(n)) {
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System.out.println(n + " is a prime number");
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} else {
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System.out.println(n + " is not a prime number");
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}
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scanner.close();
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}
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/***
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* Checks if a number is prime or not
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* @param n the number
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* @return {@code true} if {@code n} is prime
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*/
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public static boolean isPrime(int n) {
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if (n == 2) {
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return true;
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}
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if (n < 2 || n % 2 == 0) {
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return false;
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}
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for (int i = 3, limit = (int) Math.sqrt(n); i <= limit; i += 2) {
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if (n % i == 0) {
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return false;
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}
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}
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return true;
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}
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}
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