solves add to array form of integer

Author: anishLearnsToCode

README.md

@@ -265,7 +265,7 @@
 | 976 | [Largest Perimeter Triangle](https://leetcode.com/problems/largest-perimeter-triangle) | [![Java](assets/java.png)](src/LargestPerimeterTriangle.java) |
 | 977 | [Squares of a Sorted Array](https://leetcode.com/problems/squares-of-a-sorted-array) | |
 | 985 | [Sum of Even Numbers after Queries](https://leetcode.com/problems/sum-of-even-numbers-after-queries) | |
-| 989 | [Add to Array Form of Integer](https://leetcode.com/problems/add-to-array-form-of-integer) | |
+| 989 | [Add to Array Form of Integer](https://leetcode.com/problems/add-to-array-form-of-integer) | [![Java](assets/java.png)](src/AddToArrayFormOfInteger.java) |
 | 993 | [Cousins in Binary Tree](https://leetcode.com/problems/cousins-in-binary-tree) | |
 | 997 | [Find the Town Judge](https://leetcode.com/problems/find-the-town-judge) | |
 | 999 | [Available Captures for Rook](https://leetcode.com/problems/available-captures-for-rook) | |

src/AddToArrayFormOfInteger.java

@@ -0,0 +1,22 @@
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class AddToArrayFormOfInteger {
+    public List<Integer> addToArrayForm(int[] num, int k) {
+        List<Integer> result = new ArrayList<>();
+        int sum;
+        for (int i = num.length - 1, carry = 0 ; i >= 0 || carry > 0 || k > 0 ; i--, k /= 10) {
+            sum = get(num, i) + carry + k % 10;
+            result.add(sum % 10);
+            carry = sum / 10;
+        }
+        Collections.reverse(result);
+        return result;
+    }
+
+    private int get(int[] array, int index) {
+        if (index < 0) return 0;
+        return array[index];
+    }
+}