Question

I’m trying to make a function with list.
It is to sort and delete duplicates.
It sorts good, but don’t delete duplictates.
What’s the problem?

void sort_del(List<double> slist){
        //here i sort slist
        //get sorted with duplicates

        List<double> rlist = new List<double>();
        int new_i=0;
        rlist.Add(slist[0]);
        for (i = 0; i < size; i++)
        {
            if (slist[i] != rlist[new_i])
            {
                rlist.Add(slist[i]);
                new_i++;
            }

        }

        slist = new List<double>(rlist);
        //here get without duplicates
    }

Answer 1

It does not work because slist is passed by value. Assigning rlist to it has no effect on the caller’s end. Your algorithm for detecting duplicates seems fine. If you do not want to use a more elegant LINQ way suggested in the other answer, change the method to return your list:

List<double> sort_del(List<double> slist){
    // Do your stuff
    return rlist;
}