M1// gai ming! public static int palindroCount(int n) { int result = 0; if (!isPalindrome(n)) { result = 1; while (!isPalindrome(n +invert(n))) { result++; n += invert(n); if (result > 10) result = -1; } } return result; } private static int invert(int n) { String invert = ""; String number = String.valueOf(n); for (int i = 0; i < number.length(); i++) { invert += number.charAt(number.length() - 1 - i); } return Integer.parseInt(invert); } private static boolean isPalindrome(int n) { boolean result = true; String number = String.valueOf(n); for (int i = 0; i < number.length(); i++) { if (number.charAt(i) != number.charAt(number.length() - 1 - i)) result = false; } return result; } public static void main(String[] args) { System.out.println(isPalindrome(11)); System.out.println(isPalindrome(1431)); System.out.println(isPalindrome(131)); System.out.println(invert(7654)); System.out.println(palindroCount(159)); }