在素数判断方法isPrime处不知道该怎么写才能让程序跑出结果而不用等到天长地久...
public static void main(String[] args) {
long startTime = System.currentTimeMillis();
BigInteger bigNum = new BigInteger(Long.MAX_VALUE + "");
bigNum = bigNum.add(BigInteger.ONE);
int count = 1;
while (count <= 5) {
if (isPrime(bigNum)) {
System.out.println(bigNum);
count++;
}
bigNum = bigNum.add(BigInteger.ONE);
}
System.out.println(bigNum.toString());
long endTime = System.currentTimeMillis();
System.out.println("Time spent is " +
(endTime - startTime) + " milliseconds");
}
public static boolean isPrime(BigInteger num) {
return true;
}
java
的BigInteger
有自带的isProbablePrime
函数,把参数设置大一点,结果就几乎不会出错。
public static boolean isPrime(BigInteger num) {
return num.isProbablePrime(50);
}