[알고리즘] 백준 - 1406 ( 에디터 ) / 자바

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

class Main {
	public static void main(String args[]) throws IOException {
		Stack<Character> stack1 = new Stack<Character>();
		Stack<Character> stack2 = new Stack<Character>();
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringBuilder sb = new StringBuilder();
		String s = br.readLine();
		int len = s.length();
		for(int i = 0 ; i < len ; i++) {
			stack1.push(s.charAt(i));
		}
		int count = Integer.parseInt(br.readLine());
		StringTokenizer st;
		for(int i= 0  ; i  < count ; i ++) {
			st = new StringTokenizer(br.readLine());
			char type = st.nextToken().charAt(0);
			switch(type) {
			case 'P':
				stack1.push(st.nextToken().charAt(0));
				break;
			case 'L':
				if(!stack1.isEmpty()) {
					stack2.push(stack1.pop());
				}
				break;
			case 'D':
				if(!stack2.isEmpty()) {
					stack1.push(stack2.pop());
				}
				break;
			case 'B':
				if(!stack1.isEmpty()) {
					stack1.pop();
				}
				break;
			}
			
		}
		while(!stack2.isEmpty()) {
			stack1.push(stack2.pop());
		}
		while(!stack1.isEmpty()) {
			sb.append(stack1.pop());
		}
		System.out.println(sb.reverse());
		
	}
}

스택 2개를 활용하여 커서를 관리해봤다.