[BOJ/백준 - 10845] 큐

문제 출처: https://www.acmicpc.net/problem/10845

10845번: 큐

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	public class BOJ_10845 {
	public static void main(String[] args) throws IOException {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	StringTokenizer st;
	int len = Integer.parseInt(br.readLine());
	ArrayList<Integer> al = new ArrayList<>();
	for(int i=0; i<len; i++){
	st = new StringTokenizer(br.readLine());
	String temp = st.nextToken();
	if("pop".equals(temp)){
	if(al.isEmpty()){
	System.out.println(-1);
	}else{
	System.out.println(al.remove(0));
	}
	}else if("size".equals(temp)){
	System.out.println(al.size());
	}else if("empty".equals(temp)){
	if(al.isEmpty()){
	System.out.println(1);
	}else{
	System.out.println(0);
	}
	}else if("front".equals(temp)){
	if(al.isEmpty()){
	System.out.println(-1);
	}else{
	System.out.println(al.get(0));
	}
	}else if("back".equals(temp)){
	if(al.isEmpty()){
	System.out.println(-1);
	}else{
	System.out.println(al.get(al.size()-1));
	}
	}else{ // push X
	int num = Integer.parseInt(st.nextToken());
	al.add(num);
	}
	}
	}
	}

view raw BOJ_10845.java hosted with ❤ by GitHub

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그냥 편하게 어레이리스트 썼다 빨리 풀고 지나가고 싶었음