Concatenation of Array

这题没啥可说的吧..

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