989. Add to Array-Form of Integer

#### QUESTION:

For a non-negative integer X, the array-form of X is an array of its digits in left to right order. For example, if X = 1231, then the array form is [1,2,3,1].

Given the array-form A of a non-negative integer X, return the array-form of the integer X+K.

Example 1:

Input: A = [1,2,0,0], K = 34 Output: [1,2,3,4] Explanation: 1200 + 34 = 1234 Example 2:

Input: A = [2,7,4], K = 181 Output: [4,5,5] Explanation: 274 + 181 = 455 Example 3:

Input: A = [2,1,5], K = 806 Output: [1,0,2,1] Explanation: 215 + 806 = 1021 Example 4:

Input: A = [9,9,9,9,9,9,9,9,9,9], K = 1 Output: [1,0,0,0,0,0,0,0,0,0,0] Explanation: 9999999999 + 1 = 10000000000

Note：

1 <= A.length <= 10000 0 <= A[i] <= 9 0 <= K <= 10000 If A.length > 1, then A[0] != 0

#### SOLUTION:

``````class Solution {
public List<Integer> addToArrayForm(int[] A, int K) {
ArrayList<Integer> list = new ArrayList<>();
char[] KArray = (K+"").toCharArray();
int length = Math.max(A.length,KArray.length);
int carry = 0;
for(int i = 1;i<=length;i++){
int numberA = 0,numberK = 0;
if(A.length-i>=0) numberA = A[A.length-i];
if(KArray.length-i>=0) numberK = Integer.parseInt(KArray[KArray.length-i]+"");
int number = numberA+numberK+carry;
int tmp = number%10;
carry = number/10;