[C++] std::copy
Intuition\n Describe your first thoughts on how to solve this problem. \nJust do what the problem asks to do.\n\n# Approach\n Describe your approach to solving 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\nJust do what the problem asks to do.\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\nuse ```std::copy```.\n\n# Complexity\n- Time complexity: $$O(n)$$\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity: $$O(n)$$\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution {\npublic:\n    vector<int> getConcatenation(vector<int>& nums) {\n        nums.reserve(nums.size() * 2);\n        copy(nums.begin(), nums.end(), back_inserter(nums));\n        return nums;\n    }\n};\n```
['C++']