1929_Concatenation of Array.java

class Solution {
    public int[] getConcatenation(int[] nums) {
        int n = nums.length;
        int [] ans = new int [n * 2];
        for(int i = 0;i < n; i++){
            ans[i] = ans[n+i]  = nums[i];
        }
        return ans;
    }
}