230626 뉴스 클러스터링

 public int solution(String str1, String str2) {
	Set<String> set = new HashSet<>();
	Map<String, Integer> map1 = new HashMap<>();
	Map<String, Integer> map2 = new HashMap<>();

	cluster(str1.toLowerCase(), map1, set);
	cluster(str2.toLowerCase(), map2, set);

	int union = 0;
	int untersection = 0;

	for (String key : set) {
		int a = map1.getOrDefault(key, 0);
		int b = map2.getOrDefault(key, 0);
		union += Math.max(a, b);
		untersection += Math.min(a, b);
	}

	if (union == 0) {
		return 65536;
	}

	return (int) (((double) untersection / (double) union) * 65536);
}

static void cluster(String str, Map<String, Integer> map, Set<String> set) {
	for (int i = 0; i <= str.length() - 2; i++) {
		boolean flag = true;
		String s = str.substring(i, i + 2);

		for (int j = 0; j < 2; j++) {
			if (s.charAt(j) < 'a' || s.charAt(j) > 'z') {
				flag = false;
				break;
			}
		}

		if (flag) {
			set.add(s);
			map.put(s, map.getOrDefault(s, 0) + 1);
		}
	}
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/17677