1929. Concatenation of Array

Description of the Problem

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

Solution

Code(Rust)

impl Solution {
    pub fn get_concatenation(nums: Vec<i32>) -> Vec<i32> {
        let mut res = nums.clone();
        for n in nums{
            res.push(n);
        }
        return res;
    }
}

Complexity

n is the number of elements in the array

Time complexity:

\( T(n) = \Theta(n) \)

Auxiliary Space:

\( S(n) = O(n) \)

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