concatenation_of_array.py

# https://leetcode.com/problems/concatenation-of-array/description/
# 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]
# 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.length
# 1 <= n <= 1000
# 1 <= nums[i] <= 1000

from typing import List

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

print(Solution().getConcatenation([1,2,1]))
# Output: [1,2,1,1,2,1]
print(Solution().getConcatenation([1,3,2,1]))
# Output: [1,3,2,1,1,3,2,1]