HJ60 查找组成一个偶数最接近的两个素数

1. 题目

读题

HJ60 查找组成一个偶数最接近的两个素数 

 

考查点

 

2. 解法

思路

 

代码逻辑

 

具体实现

public class HJ60 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        getPrimeNum(n);

    }

    public static void getPrimeNum(int n) {

        int first = 0, second = 0, diff = n;
        for (int i = n / 2; i >= 2; i--) {
            if (Math.abs(n - 2 * i) < diff && isPrime(i) && isPrime(n - i)) {
                first = i;
                second = n - i;
                diff = Math.abs(second - first);
            }
        }
        if (first != 0) {
            System.out.println(first);
            System.out.println(second);
        }

    }

    public static boolean isPrime(int n) {
        boolean flag = true;
        for (int i = 2; i * i <= n; i++) {
            if (n % i == 0) {
                return false;
            }
        }
        return true;
    }
}

 

3. 总结