Write a recursive method that generates a list of all possible character strings of a given length for a given numeric base. For example, generating all base 2 strings of length 3 should yield [000, 001, 010, 011, 100, 101, 110, 111]. Generating all base 4 strings of length 2 should yield [00, 01, 02, 03, 10, 11, 12, 13, 20, 21, 22, 23, 30, 31, 32, 33]. Feel free to use a helper method if needed. Bases less than 2 should be rejected as should strings of length 0 or less.

public static List generateAllStrings(int length, int base) {

// insert your code here

}

Problem