Question

Lets say there is an array like this:

double [] numbers = new double[] {1,1,2,2,5,7,7,7};

I want to copy only the different numbers to a new array (the result should be numbers = {1,2,5,7}) in a time efficient way. I know how to do it in a time inefficient way – by looking if the next number is the same as the one before and continuing the copy loop if they are. Is there another way?

Answer 1

If you don’t have Linq, you can do the following:

List<double> uniques = new List<double>;
foreach (double num in numbers)
{
  if (!uniques.Contains(num)) uniques.Add(num);
}

double[] uniquearray = uniques.ToArray();