Given an integer array nums of length n, you want to 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 = [1,2,1] +Output: [1,2,1,1,2,1] +Explanation: The array ans is formed as follows: +- ans = [nums[0],nums[1],nums[2],nums[0],nums[1],nums[2]] +- ans = [1,2,1,1,2,1]+ +
Example 2:
+ +Input: nums = [1,3,2,1] +Output: [1,3,2,1,1,3,2,1] +Explanation: The array ans is formed as follows: +- ans = [nums[0],nums[1],nums[2],nums[3],nums[0],nums[1],nums[2],nums[3]] +- ans = [1,3,2,1,1,3,2,1] ++ +
+
Constraints:
+ +n == nums.length1 <= n <= 10001 <= nums[i] <= 1000