240102 택배상자

public int solution(int[] order) {
	Queue<Integer> workingQueue = new LinkedList<>();
	Stack<Integer> waitingStack = new Stack<>();

	int cnt = 0;

	for (int i = 0; i < order.length; i++) {
		waitingStack.add(i + 1);

		while (!waitingStack.isEmpty()) {
			if (waitingStack.peek() == order[cnt]) {
				workingQueue.offer(waitingStack.pop());
				cnt++;
			} else {
				break;
			}
		}
	}

	return workingQueue.size();
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/131704