C / C++ / Python Simple and Short Solutions
C++:\nSolution I\n\nclass Solution {\npublic:\n    vector<int> getConcatenation(vector<int>& nums) {\n        nums.insert( nums.end(), nums.begin(), nums.end() 
**C++:**\nSolution I\n```\nclass Solution {\npublic:\n    vector<int> getConcatenation(vector<int>& nums) {\n        nums.insert( nums.end(), nums.begin(), nums.end() );\n        return nums;\n    }\n};\n```\nSolution II\n```\nclass Solution {\npublic:\n    vector<int> getConcatenation(vector<int>& nums) {\n        int n = nums.size();\n        for (int i = 0; i < n; i++) nums.push_back(nums[i]);\n        return nums;\n    }\n};\n```\n**C:**\n```\nint* getConcatenation(int* nums, int numsSize, int* returnSize){\n    int* res = (int*)malloc(sizeof(int) * numsSize*2);\n    *returnSize = 2 * numsSize;\n    for (int i = 0; i < numsSize; i++) {\n        res[i] = res[i+numsSize] = nums[i];\n    }\n    return res;\n}\n```\n**Python One-Liner:**\n```\nclass Solution:\n    def getConcatenation(self, nums: List[int]) -> List[int]:\n        return nums*2\n```\n**Like it? please upvote!**
['C', 'Python']