Leetcode 1929. Concatenation of Array
Intuition
Loop through input array and fill answer array in one pass.
Approach
In one forloop set the ans[i] and ans[i + nums.Length]
to the current value at nums[i].
Code
public class Solution
{
public int[] GetConcatenation(int[] nums)
{
var numsLength = nums.Length;
var ansLength = numsLength * 2;
int[] ans = new int[ansLength];
for(int i = 0; i < numsLength; i++)
{
ans[i] = nums[i];
ans[i + numsLength] = nums[i];
}
return ans;
}
}