/* Given a non-negative number represented as an array of digits, plus one to the number.

* The digits are stored such that the most significant digit is at the head of the list.

*/

public class plusOne{

public static int[] plusOne(int[] digits) {

int carry = 0;

int i = digits.length - 1;

if (digits[i] != 9) {

digits[i] += 1;

return digits;

} else {

digits[i] = 0;

carry += 1;

for (int k = i - 1; k >= 0; k--) {

if(digits[k] != 9) {

digits[k] += 1;

carry -= 1;

} else {

digits[k] = 0;

}

if (carry == 0) {

break;

}

} // close for

if (digits[0] != 0) {

return digits;

} else {

int[] result = new int[digits.length + 1];

result[0] = 1;

return result;

} // close if-else

} // close if-else

} // close plusOne method

public static void main(String[] args) {

int[] n = {1, 8, 9, 9};

int[] r = plusOne(n);

for (int k = 0; k < r.length; k++) {

System.out.print(r[k] + ",");

} // close for

} // close main

}