The intuition behind solving this problem is to concatenate the given list with itself. This means we will simply append the elements of the list to itself, creating a new list that is a concatenation of the original list with itself.

To implement this approach, we will extend the original list with a copy of itself. This can be done by using the extend method available for Python lists. The extend method takes an iterable (in this case, the original list) and appends its elements to the end of the list.

• Time complexity:The time complexity of this approach is O(n), where n is the length of the input list nums. The extend operation takes linear time.

• Space complexity:The space complexity is also O(n), as we are creating a new list of the same length as the input list.

class Solution:
    def getConcatenation(self, nums: List[int]) -> List[int]:
        nums.extend(nums)
        return nums     

Python