Concatenation of Array
You are given an integer array nums of length n. Create an array ans of length 2n where ans[i] == nums[i] and ans[i + n] == nums[i] for 0 <= i < n (0-indexed).
Specifically, ans is the concatenation of two nums arrays.
Return the array ans.
Example 1:
Input: nums = [1,4,1,2]
Output: [1,4,1,2,1,4,1,2]Example 2:
Input: nums = [22,21,20,1]
Output: [22,21,20,1,22,21,20,1]Constraints:
1 <= nums.length <= 1000.1 <= nums[i] <= 1000