求一個整數是否爲素數(質數)
public class CMath { private CMath() {} /** * Determine whether an integer is a prime. * * @param n the integer * @return result */ public static boolean isPrime(int n) { if (n < 2) return false; for (int i = 2; i * i < n; i++) { if (n % i == 0) return false; } return true; } }