231127 보석 쇼핑

public int[] solution(String[] gems) {
	Map<String, Integer> gemCount = new HashMap<>();
	Set<String> uniqueGems = new HashSet<>();
	Queue<String> gemQueue = new LinkedList<>();

	int minLength = gems.length + 1;
	int start = 0;
	int startIndex = 0;

	uniqueGems.addAll(Arrays.asList(gems));

	for (int i = 0; i < gems.length; i++) {
		gemCount.put(gems[i], gemCount.getOrDefault(gems[i], 0) + 1);
		gemQueue.add(gems[i]);

		while (gemCount.get(gemQueue.peek()) > 1) {
			gemCount.put(gemQueue.peek(), gemCount.get(gemQueue.poll()) - 1);
			startIndex++;
		}

		if (gemCount.size() == uniqueGems.size() && minLength > (i - startIndex)) {
			minLength = i - startIndex;
			start = startIndex + 1;
		}
	}

	return new int[] { start, start + minLength };
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/67258