AddToArrayForm-LCQ.cpp

/*
Add to Array-Form of Integer

The array-form of an integer num is an array representing its digits in left to right order.

For example, for num = 1321, the array form is [1,3,2,1].
Given num, the array-form of an integer, and an integer k, return the array-form of the integer num + k.



Example 1:

Input: num = [1,2,0,0], k = 34
Output: [1,2,3,4]
Explanation: 1200 + 34 = 1234

Example 2:

Input: num = [2,7,4], k = 181
Output: [4,5,5]
Explanation: 274 + 181 = 455

Example 3:

Input: num = [2,1,5], k = 806
Output: [1,0,2,1]
Explanation: 215 + 806 = 1021


Constraints:

1 <= num.length <= 104
0 <= num[i] <= 9
num does not contain any leading zeros except for the zero itself.
1 <= k <= 104
*/

class Solution {
public:
	vector<int> addToArrayForm(vector<int>& num, int k) {
		for (int i = num.size() - 1; i >= 0; i--) {
			num[i] += k;
			k = num[i] / 10;
			num[i] %= 10;
		}
		while (k > 0) {
			num.insert(num.begin(), k % 10);
			k /= 10;
		}
		return num;
	}
};