[알고리즘] 백준 - 5430 ( AC) / 자바

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Deque;
import java.util.LinkedList;
import java.util.StringTokenizer;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		int TC = Integer.parseInt(br.readLine());
		StringBuilder sb = new StringBuilder("");
tc:		for (int i = 0; i < TC; i++) {
			
			String func = br.readLine(); // RDD
			boolean isReverse = false;
			int size = Integer.parseInt(br.readLine()); // 4
			Deque<Integer> deque = new LinkedList<>();
			String temp = br.readLine().replace("[", "").replace("]", "").replace(",", " ");
			StringTokenizer st = new StringTokenizer(temp);
			for (int j = 0; j < size; j++) { // [1,2,3,4]
				deque.add(Integer.parseInt(st.nextToken()));
			}

			for (char c : func.toCharArray()) {
				if (c == 'R') {
					isReverse = !isReverse;
				} else { // D 일때
					if (deque.isEmpty()) {
						sb.append("error").append("\n");
						continue tc;
					}
					if (isReverse) {// 역순이면
						deque.removeLast();
					} else {
						deque.removeFirst();
					}
				}

			}
			sb.append("[");
			while (!deque.isEmpty()) {
				if (isReverse) {
					if(size==1) {
						sb.append(deque.removeLast());
						continue;
					}
					sb.append(deque.removeLast()).append(",");
				} else {
					sb.append(deque.removeFirst()).append(",");
				}
			}
			if(size > 1 ) {
				sb.deleteCharAt(sb.lastIndexOf(","));	
			}			
			sb.append("]").append("\n");

			
		}
		System.out.print(sb);
	}

}

최적화 다시 해볼것