231011 숫자 카드 나누기

public int solution(int[] arrayA, int[] arrayB) {
	int gcdA = calculateGCD(arrayA);
	int gcdB = calculateGCD(arrayB);

	gcdA = updateGCD(gcdA, arrayB);
	gcdB = updateGCD(gcdB, arrayA);

	if (gcdA == gcdB) {
		return 0;
	} else {
		return Math.max(gcdA, gcdB);
	}
}

public int calculateGCD(int[] arr) {
	int gcd = arr[0];
	for (int i = 1; i < arr.length; i++) {
		gcd = calculateGCD(gcd, arr[i]);
	}
	return gcd;
}

public int calculateGCD(int a, int b) {
	if (a == 0) {
		return b;
	}
	return calculateGCD(b % a, a);
}

public int updateGCD(int gcd, int[] arr) {
	for (int i = arr.length - 1; i >= 0; i--) {
		if (arr[i] % gcd == 0) {
			gcd = 1;
			break;
		}
	}
	return gcd;
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/135807