240315 멀쩡한 사각형

public long solution(int w, int h) {
	long area = (long) w * h;

	if (w == 1 || h == 1) {
		return 0;
	}

	long gcd = calculateGcd(w, h);
	long overlappedArea = (w / gcd) + (h / gcd) - 1;
	return area - gcd * overlappedArea;
}

public long calculateGcd(long a, long b) {
	if (b == 0) {
		return a;
	}
	return calculateGcd(b, a % b);
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/62048