231211 캐시

public int solution(int cacheSize, String[] cities) {
	if (cacheSize == 0)
		return cities.length * 5;

	int answer = 0;
	LinkedList<String> cache = new LinkedList<>();

	for (int i = 0; i < cities.length; i++) {
		String cityName = cities[i].toUpperCase();

		if (cache.remove(cityName)) {
			answer += 1;
			cache.add(cityName);
		} else {
			answer += 5;
			if (cache.size() >= cacheSize) {
				cache.remove(0);
			}
			cache.add(cityName);
		}
	}
	return answer;
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/17680