Simple and Intutive Solution
Intuition \n\nThe problem involves adding a large integer represented as an array (num) to another integer (k). The idea is to simulate the addition process as 
# Intuition \n\nThe problem involves adding a large integer represented as an array (`num`) to another integer (`k`). The idea is to simulate the addition process as we do manually, digit by digit from right to left.\n\nConsider this example:\n- `num = [1, 2, 3]` (which represents 123)\n- `k = 789`\n\n### The approach:\n1. Start from the last digit of `num` (i.e., the least significant digit) and add it to the last digit of `k`.\n2. If there\'s a carry, it will be added to the next digit in the next iteration.\n3. Continue this process, moving from right to left across `num`, while simultaneously reducing `k` by dividing it by 10.\n4. The loop continues until there are no digits left in both `num` and `k`.\n\nThe result is stored in reverse order as we append digits to the front of the list (or reverse the list later).\n\n# Complexity\n\n- **Time Complexity:** \\( O(n + \\log_{10} k) \\)\n    - We traverse through the array `num` which has `n` elements.\n    - Additionally, in each iteration, we reduce `k` by dividing it by 10, which takes \\( \\log_{10} k \\) steps.\n    - Since `k` could have more digits than `num`, the time complexity can be considered as \\( O(\\max(n, \\log_{10} k)) \\).\n\n- **Space Complexity:** \\( O(n + \\log_{10} k) \\)\n    - The space is used to store the result. Although we\u2019re not using any additional auxiliary space apart from the result list, the size of this list could be as large as the number of digits in `num` or `k`.\n\n\n# Code\n```\nclass Solution {\n    public List<Integer> addToArrayForm(int[] num, int k) {\n        int n = num.length;\n        ArrayList<Integer> list = new ArrayList<>();\n        int i = n - 1;\n        while (i >= 0 || k > 0) {\n            if (i >= 0) {\n                k += num[i];\n            }\n            list.add(0, k % 10);\n            k /= 10;\n            i--;\n        }\n        return list;\n    }\n}\n```
['Java']