这是一个既没有array也没有arraylist的版本。结果将按您的要求打印到标准输出。
String[] allLetters = new String[] { "0", "1", "ABC", "DEF", "GHI", "JKL", // etc... };public static void convert(String phoneNumber){ convertSubstring(phoneNumber,"");}private static void convertSubstring(String phoneNumber, String convertedLetters){ int digit = Integer.parseInt(phoneNumber.substring(0, 1)); String letters=allLetters[digit]; String remainingString=phoneNumber.substring(1); for (int i = 0; i < letters.length(); ++i) { char letter = letters.charAt(i); String result=convertedLetters+letter; if (remainingString.length()==0) System.out.println(result); else convertSubstring(remainingString, result); }}
