Concatenation of array

Array Simulation

90.5% acceptance

Feb 25, 2026

4125

450

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.

Solution

Rust

Time O(1)

Space O(1)

LeetCode

solution.rs

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