Kotlin solution
Complexity\n\n- Time complexity: $O(n)$\n- Space complexity: $O(n)$\n\n# Code\n\n\nclass Solution {\n    fun getConcatenation(nums: IntArray): IntArray =\n     
# Complexity\n\n- Time complexity: $O(n)$\n- Space complexity: $O(n)$\n\n# Code\n\n```\nclass Solution {\n    fun getConcatenation(nums: IntArray): IntArray =\n        IntArray(nums.size * 2) { nums[it % nums.size] }\n}\n```
['Kotlin']