큐 클래스 (Queue)

interface Collection{
	int MAX = 100;
	void add(Object obj);
	void delete(Object obj);
	Object find(Object obj);
	int currentCount();
}
class Queue implements Collection{
	private Object[] queue = new Object[MAX];
	private int rear = -1;
	private int front = 0;
	private int count = 0;
	public void add(Object obj) {
		queue[++rear] = obj;
		count++;
	}
	public void delete(Object obj) {
		for(int i=front; i<rear; i++) {
			if(queue[i]==obj)
				queue[i]=null;
		}
		front++;
		count--;
	}
	public Object find(Object obj) {
		for(int i=front; i<rear; i++) {
			if(queue[i]==obj) {
				return i;
			}
		}
		return null;
	}
	public int currentCount() {
		return count;
	}
}
public class chp6_9 {
	public static void main(String[] args) {
		Queue q = new Queue();
		q.add(3);
		q.add(4);
		q.add(5);
		
		System.out.println(q.find(4));
		System.out.println(q.currentCount());
		
		q.delete(4);		
		System.out.println(q.find(4));		
		System.out.println(q.currentCount());
	}
}