repeater string not allowed

Question

I have a text file which contains lines of string for example:

a, b, c, d, e, d
t, e, rt, q, r, e, t, w, d, t

I need to make sure that in each line I read from a file, no repeater character or string is allowed.I need to check and make sure there is no repeater character in each line.So how would I check that?

I'm thinking of creating 2d array and check it but then in each line has unlimited length.Is there any other way of checking it?

Answer 1

Use a HashSet for each line to store the already read values.

The algorithm would be something like this (roughly)

HashSet<string> hashSet = new HashSet<string>();
bool hasDuplicate = false;
string[] lineEntries = line.split(", ");
foreach (string s in lineEntries)
{
   if (hashSet.contains(s))
      hasDuplicate = true;
   hashSet.add(s);
}

That's the code for one line only. You could expand this for all the lines.