How can you remove duplicate characters in a string?

Question

I have to implements a function that takes a string as an input and finds the non-duplicate character from this string.

So an an example is if I pass string str = \"

Answer 1

//this is in C#, validation left out for brevity //primitive solution for removing duplicate chars from a given string

    public static char[] RemoveDup(string s)
    {
        char[] c = new char[s.Length];
        int unique = 0;
        c[unique] = s[0];  // Assume: First char is trivial
        for (int i = 1; i < s.Length; i++)
        {
            if (s[i-1] != s[i]
        c[++unique] = s[i];
        }
        return c;
    }