C++ SOLUTION || 2 LINES || NO EXTRA VECTOR
\n vector<int> getConcatenation(vector<int> &nums)\n    {\n        nums.insert(nums.end(), nums.begin(), nums.end());\n        return nums;\n    }\n
```\n vector<int> getConcatenation(vector<int> &nums)\n    {\n        nums.insert(nums.end(), nums.begin(), nums.end());\n        return nums;\n    }\n```
['C', 'C++']