1929.concatenation_of_array

1929. Concatenation of Array

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]

Example 2:

Input: nums = [1,3,2,1]
Output: [1,3,2,1,1,3,2,1]

Constraints:

• n == nums.length
• 1 <= n <= 1000
• 1 <= nums[i] <= 1000