[Silver 3] 17413번 단어 뒤집기 2

import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        Stack<String> stack = new Stack<>();
        Queue<String> queue = new LinkedList<>();
        StringBuilder sb = new StringBuilder();
        String[] arr = br.readLine().split("");
        boolean tag = false;
        
        for(String s : arr) {
            if(tag) {
                queue.add(s);
                if(s.equals(">")) {
                    while(!queue.isEmpty()) { sb.append(queue.poll()); }
                    tag = false;
                }
                continue;
            }
            
            if(s.equals("<")) {
                if(!stack.isEmpty()) {
                    while(!stack.isEmpty()) { sb.append(stack.pop()); }
                }
                queue.add(s);
                tag = true;
                continue;
            }
            
            if(s.equals(" ")) {
                while(!stack.isEmpty()) { sb.append(stack.pop()); }
                sb.append(s);
                continue;
            }
            
            stack.push(s);
        }
        
        while(!stack.isEmpty()) { sb.append(stack.pop()); }
        System.out.println(sb);
    }
}