2 approaches - Using Python Built-In Functions & Maths - Explained with comments
Using Built-in functions\n\nimport sys\nclass Solution:\n    def addToArrayForm(self, num: List[int], k: int) -> List[int]:\n        # Set the maximum number of
#### Using Built-in functions\n```\nimport sys\nclass Solution:\n    def addToArrayForm(self, num: List[int], k: int) -> List[int]:\n        # Set the maximum number of digits allowed in an integer to handle large numbers\n        # sys.set_int_max_str_digits(100000) is used to prevent overflow errors in large integer operations\n        sys.set_int_max_str_digits(100000) # ******** Important ***************\n        \n        # Convert the list of digits in \'num\' to a string, then concatenate the string into a single integer.\n        # Example: num = [1,2,3] -> \'123\' -> 123\n        int_num = int(\'\'.join(map(str, num)))\n        \n        # Add the integer \'k\' to the integer representation of \'num\'\n        ans_int = int_num + k\n        \n        # Convert the resulting integer back into a string, then split the string into a list of characters (digits)\n        # Example: 456 -> \'456\' -> [\'4\', \'5\', \'6\']\n        ans_str_list = list(str(ans_int))\n        \n        # Map each character (digit) back to an integer, converting the string digits to integers\n        # Example: [\'4\', \'5\', \'6\'] -> [4, 5, 6]\n        ans_int_list = list(map(int, ans_str_list))\n        \n        # Return the final result, which is the array-form of the sum of \'num\' and \'k\'\n        return ans_int_list\n```\n---\n#### Using Maths\n```\nclass Solution:\n    def addToArrayForm(self, num: List[int], k: int) -> List[int]:\n        # Initialize a pointer to the last digit of the num array\n        i = len(num) - 1\n        \n        # Process the addition from the last digit of the array and k\n        while k > 0:\n            # If i is still within the bounds of the num array, add k to the current digit\n            if i >= 0:\n                # Add the last digit of k to the num[i] (adding carry to the num)\n                num[i] += k\n                # Calculate the carry by performing integer division by 10\n                k = num[i] // 10\n                # Update the current digit in num after removing the carry\n                num[i] %= 10\n                # Move to the previous digit in the num array\n                i -= 1\n            else:\n                # If i is out of bounds, treat the remaining k as the carry to be inserted at the front\n                num.insert(0, k % 10)  # Insert the last digit of k to the front of the array\n                k //= 10  # Remove the last digit from k (carry)\n        \n        return num  # Return the resulting array-form after addition\n```\n**Please UpVote if you like the Code and Explanation**
['Python3']