Java思路：使用String的字符串处理以及ArrayList的列表处理。

Java代码：

import java.util.ArrayList;
import java.util.Scanner;
public class Main{
    public static ArrayList<String> list = new ArrayList<>();
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        String s = sc.nextLine();
        for (int i = 0; i < n; i++) {
            String str = sc.nextLine();
            String[] strArr = str.split(" ");
            if ("ls".equals(strArr[0])){
                for (int j = 0; j < list.size(); j++) {
                    System.out.println(list.get(j));
                }
            }else if ("rm".equals(strArr[0]) && list.indexOf(strArr[1]) != -1){
                list.remove(list.indexOf(strArr[1]));
            }else if ("touch".equals(strArr[0]) && list.indexOf(strArr[1]) == -1){
                list.add(strArr[1]);
            }else rename(strArr[1],strArr[2]);
        }
    }
    public static void rename(String fromName,String toName){
        if (list.indexOf(fromName) == -1){
            list.add(toName);
        }else {
            list.set(list.indexOf(fromName),toName);
        }
    }
}