Question

java编程 有没有会这题的 谢谢帮忙

Answer 1

Java程序如下：
public class Test {

public static void main(String[] args) {

for(int i=3; i<1000; i+=2) {

if(isPrime(i) && isPrime(i+2)) {

System.out.printf("(%d, %d)\n", i, i+2);

}

}

}

static boolean isPrime(int x) {

int k = (int) Math.sqrt(x);

for(int i=2; i<=k; i++) {

if(x % i == 0) {

return false;

}

}

return true;

}

}

运行结果：

(3, 5)

(5, 7)

(11, 13)

(17, 19)

(29, 31)

(41, 43)

(59, 61)

(71, 73)

(101, 103)

(107, 109)

(137, 139)

(149, 151)

(179, 181)

(191, 193)

(197, 199)

(227, 229)

(239, 241)

(269, 271)

(281, 283)

(311, 313)

(347, 349)

(419, 421)

(431, 433)

(461, 463)

(521, 523)

(569, 571)

(599, 601)

(617, 619)

(641, 643)

(659, 661)

(809, 811)

(821, 823)

(827, 829)

(857, 859)

(881, 883)