Regular Extensions

import java.util.HashSet;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class myClass {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);

        String text = s.nextLine();
        String pattern;
        while (!(pattern = s.nextLine()).equals("Print")) {
            pattern = formatPattern(pattern);

            Pattern p = Pattern.compile(pattern);
            Matcher m = p.matcher(text);
            while (m.find()) {
                String reversed = new StringBuilder(m.group(0)).reverse().toString();
                text = text.replace(m.group(0), reversed);
            }
        }
        System.out.println(text);
    }

    private static String formatPattern(String pattern) {
        StringBuilder sb = new StringBuilder();
        HashSet<Character> toEscape = new HashSet<>();
        char[] toEscapeArr = {'.', '^', '$', '*', '+', '?', '(', ')', '[', '{', '\\', '|'};
        for (char c : toEscapeArr) {
            toEscape.add(c);
        }
        for (int i = 0; i < pattern.length(); i++) {
            char c = pattern.charAt(i);
            if (c == '%') {
                sb.append("\\S*");
            } else if (toEscape.contains(c)) {
                sb.append('\\').append(c);
            } else {
                sb.append(c);
            }
        }
        return sb.toString();
    }
}