# Plus One

## Problem

You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0’s.

Increment the large integer by one and return the resulting array of digits.

Example 1:

```
Input: digits = [1,2,3]
Output: [1,2,4]
Explanation: The array represents the integer 123.
Incrementing by one gives 123 + 1 = 124.
Thus, the result should be [1,2,4].
```

Example 2:

```
Input: digits = [4,3,2,1]
Output: [4,3,2,2]
Explanation: The array represents the integer 4321.
Incrementing by one gives 4321 + 1 = 4322.
Thus, the result should be [4,3,2,2].
```

Example 3:

```
Input: digits = [9]
Output: [1,0]
Explanation: The array represents the integer 9.
Incrementing by one gives 9 + 1 = 10.
Thus, the result should be [1,0].
```

Constraints:

- 1 <= digits.length <= 100
- 0 <= digits[i] <= 9
- digits does not contain any leading 0’s.

### Solution

```
class Solution {
public int[] plusOne(int[] digits) {
var carry = true;
for (int i = digits.length - 1; i >= 0; i--) {
if (digits[i] == 9) {
digits[i] = 0;
} else {
digits[i] = digits[i] + 1;
carry = false;
break;
}
}
if (carry) {
// re-alloc array
var newArr = new int[digits.length + 1];
for (var i = 1; i < digits.length; i++) {
newArr[i - 1] = digits[i];
}
newArr[0] = 1;
return newArr;
} else {
return digits;
}
}
}
```