Euler P23.java

public void p23() {
	int[] dif = new int[28124];

	for (int i = 1; i < dif.length; i++) {
		dif[i] = type(i);
	}

	int sum = 0;

	for (int i = 1; i < dif.length; i++) {
		boolean a = true;

		for (int j = 1; a && j < i; j++) {
			if (dif[j] > 0 && dif[i - j] > 0) {
				a = false;
			}
		}

		if (a) {
			sum += i;
		}
	}

	System.out.println(sum);
}

public int type(int num) {
	int sum = 1;

	for (int i = 2; i < (num / 2) + 1; i++) {
		if (num % i == 0) {
			sum += i;
		}
	}

	return sum - num;
}