Simple JAVA Solution for beginners. 4ms.
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution {\n    public int[] separateDigits(int[] nums) {\n        List<Integer> AL = new ArrayList();\n        int temp;\n        for(int i = nums.length - 1; i >= 0; i--) {\n            temp = nums[i];\n            while(temp > 0){\n                AL.add(temp % 10);\n                temp /= 10;\n            }\n        }\n        int answer[] = new int[AL.size()];\n        int index = 0;\n        for(int i = AL.size() - 1; i >= 0; i--) {\n            answer[index++] = AL.get(i);\n        }\n        return answer;\n    }\n}\n```
['Array', 'Simulation', 'Java']