public class Mima { private static Map<String, String> map = new HashMap<>(); static { map.put("1", "a"); map.put("2", "b"); map.put("3", "c"); map.put("4", "d"); map.put("5", "e"); map.put("6", "f"); map.put("7", "g"); map.put("8", "h"); map.put("9", "i"); map.put("10", "j"); map.put("11", "k"); map.put("12", "l"); map.put("13", "m"); map.put("14", "n"); map.put("15", "o"); map.put("16", "p"); map.put("17", "q"); map.put("18", "r"); map.put("19", "s"); map.put("20", "t"); map.put("21", "u"); map.put("22", "v"); map.put("23", "w"); map.put("24", "x"); map.put("25", "y"); map.put("26", "z"); } public static void main(String[] args) { Scanner sc = new Scanner(System.in); while (sc.hasNext()) { String str = sc.nextLine(); StringBuilder res = new StringBuilder(); helper(str, 0, res, new StringBuilder()); System.out.println(res.substring(0, res.length() - 1)); } sc.close(); } /** * * @param str * @param size 当前可以使用的字符的下标 * @param res 存放结果 */ private static void helper(String str, int size, StringBuilder res, StringBuilder tmp) { if (size == str.length()) { res.append(tmp.toString()).append(" "); return; } String tmpStr = str.substring(size, size + 1); if (map.get(tmpStr) != null) { tmp.append(map.get(tmpStr)); helper(str, size + 1, res, tmp); tmp.deleteCharAt(tmp.length() - 1); } if (size + 2 <= str.length()) { tmpStr = str.substring(size, size + 2); if (map.get(tmpStr) != null) { tmp.append(map.get(tmpStr)); helper(str, size + 2, res, tmp); tmp.deleteCharAt(tmp.length() - 1); } } } }