一个偶数可以分解为两个质数相加

public static void zhishu() { int a = 800; for (int m = 3; m <= a/2; m++) { int k = (int)Math.sqrt(m); int i = 2; while (m % i != 0 && i <= k) { i++; } if (i > k) { int n = a - m; k = (int)Math.sqrt(n); int j = 2; while (n % j != 0 && j <= k) { j++; } if (j > k) { System.out.println(a + "=" + m + "+" + n); } } } }