Really simple Java Solution 0 ms, faster than 100.00% of Java online submissions
\nclass Solution {\n    public int[] getConcatenation(int[] nums) {\n        int arr[] = new int[(nums.length * 2)];\n        for(int i = 0; i < nums.length; i+
```\nclass Solution {\n    public int[] getConcatenation(int[] nums) {\n        int arr[] = new int[(nums.length * 2)];\n        for(int i = 0; i < nums.length; i++){\n\t\t\t//first half of output array\n            arr[i] = nums[i];\n\t\t\t//second half of output array\n            arr[i + nums.length] = nums[i];\n        }\n        return arr;\n    }\n}\n```
['Java']