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

1929. Concatenation of Array
struct Solution;

impl Solution {
    fn get_concatenation(nums: Vec<i32>) -> Vec<i32> {
        [nums.clone(), nums].concat()
    }
}

#[test]
fn test() {
    let nums = vec![1, 2, 1];
    let res = vec![1, 2, 1, 1, 2, 1];
    assert_eq!(Solution::get_concatenation(nums), res);
    let nums = vec![1, 3, 2, 1];
    let res = vec![1, 3, 2, 1, 1, 3, 2, 1];
    assert_eq!(Solution::get_concatenation(nums), res);
}