Easy C++  O(N)  Solution ||  No fancy
\nclass Solution {\npublic:\n    vector<int> getConcatenation(vector<int>& nums) {\n        int n=nums.size();\n        for(int i=0;i<n;i++)\n        {\n       
```\nclass Solution {\npublic:\n    vector<int> getConcatenation(vector<int>& nums) {\n        int n=nums.size();\n        for(int i=0;i<n;i++)\n        {\n            nums.push_back(nums[i]);\n        }\n        return nums;\n    }\n};\n```\n**Upvote if this helps you :)**
['C']