public static List<String> vanity(List<String> codes, List<String> numbers) {
		//avoid duplicated input
        Set<String> uniqueNumbers = new HashSet<>(numbers);
        Set<String> uniqueCodes = new HashSet<>(codes);

        // generate the keypad
			Map<Character, Integer> t9Keymap = new HashMap<>();
        char character = 'A' - 1;
        for (int i = 2; i < 10; i++) {
            for (int j = 0; j < 3; j++) {
                t9Keymap.put(++character, i);
            }
            if (i == 7 || i == 9) {
                t9Keymap.put(++character, i);
            }
        }
        System.out.println(t9Keymap);


        //translate codes to "numbers"
        List<String> transformedCodes = new ArrayList<>();
        uniqueCodes.forEach(code -> {
            code = code.toUpperCase();
            StringBuilder numbersFromCodeBuilder = new StringBuilder();
            code.chars().forEach(c -> numbersFromCodeBuilder.append(t9Keymap.get((char) c)));

            transformedCodes.add(numbersFromCodeBuilder.toString());

        });
        System.out.println(transformedCodes);


        //search the codes in the numbersList
        List<String> result = new ArrayList<>();
        uniqueNumbers.forEach(number -> transformedCodes.forEach(code -> {
                    if (number.contains(code)) {

                        result.add(number);
                    }
                })
        );


        // sort and return the array
        result.sort(String::compareTo);
        System.out.println(result);

        return result;
    }