Palindromic Decomposition

import java.util.Scanner;
import java.util.List;
import java.util.ArrayList;

public class PalindromicDecomposition {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int t = sc.nextInt();
        sc.nextLine();
        while (t-- > 0) {
            String s = sc.nextLine();
            printNestedListOfString(palindromicPartitioning(s));
        }
    }

    public static List<List<String>> palindromicPartitioning(String input) {
        List<List<String>> result = new ArrayList<>();
        palindromicPartitioningHelper(input, 0, new ArrayList<String>(), result);
        return result;
    }

    public static void palindromicPartitioningHelper(String input, int idx, List<String> soFar, List<List<String>> result) {
        if (idx == input.length()) {
            result.add(new ArrayList<>(soFar));
            return;
        }

        for (int i = idx + 1; i <= input.length(); i++) {
            String prefix = input.substring(idx, i);
            if (isPalindrome(prefix)) {
                soFar.add(prefix);
                palindromicPartitioningHelper(input, i, soFar, result);
                soFar.remove(soFar.size() - 1);
            }
        }
    }

    public static boolean isPalindrome(String s) {
        for (int i = 0, j = s.length() - 1; i < j; i++, j--) {
            if (s.charAt(i) != s.charAt(j)) {
                return false;
            }
        }
        return true;
    }

    public static void printNestedListOfString(List<List<String>> outer) {
        StringBuilder sb = new StringBuilder();
        sb.append('[');
        for (List<String> inner : outer) {
            sb.append(inner.toString()).append(", ");
        }
        sb.deleteCharAt(sb.length() - 1);
        sb.deleteCharAt(sb.length() - 1);
        sb.append(']');
        System.out.println(sb.toString());
    }
}