It wasn't as easy as doing a set difference as the a needed to keep the duplicate values.
Below is the answer in C#.
public class Kata
public static int ArrayDiff(int a, int b)
var hash = new HashSet<int>(b);
return a.Where(_ => !hash.Contains(_)).ToArray();
We’re a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.