1929. Concatenation of Array
Description
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
Solutions
Solution 1: Simulation
We directly simulate according to the problem description by adding the elements of $\textit{nums}$ to the answer array one by one, and then adding the elements of $\textit{nums}$ to the answer array again.
The time complexity is $O(n)$, and the space complexity is $O(n)$. Here, $n$ is the length of the array $\textit{nums}$.
1 2 3 |
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1 2 3 4 5 6 7 8 9 10 |
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1 2 3 4 5 6 7 8 9 |
|
1 2 3 |
|
1 2 3 |
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1 2 3 4 5 |
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1 2 3 4 5 6 7 |
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1 2 3 4 5 6 7 8 9 10 11 |
|