How to generate a file with all possible 12 character letter/number combinations?

Question

I have been struggling with this for some time, and I can't even figure out where could I start with it. I am trying to create a program that is going to generate a lot of random (I could call them serials). Limit would be from letter A-Z on english uppercase alphabet and numbers from 0-9.

Something like website application at this page http://www.random.org/strings/

but

I would like it to create "all" combinations, none same, of letters and numbers, and save them to text file. I think there are around 200k+ combinations.

They would be 12 characters. Example:

• T9T1P63WBYYZ
• SCI1V7SAV9F5
• 5OLN7UQS7MIE

I would like to create it in C# if it is possible, but I have no idea where should I even start. I'm browsing google and similar projects for around a week, and I need it as university project. If someone would help I would be very happy.

Answer 1

Hehe.. if you have the time!

Asked yesterday, seen a great solution by L.B here:

How to get all the possible 3 letter permutations?

His simple solution, just change the alphabet:

var alphabet = "abcdefghijklmnopqrstuvwxyz1234567890";

var query = from a in alphabet
            from b in alphabet
            from c in alphabet
            from d in alphabet
            from e in alphabet
            from f in alphabet
            from g in alphabet
            from h in alphabet
            from i in alphabet
            from j in alphabet
            from k in alphabet
            from l in alphabet

            select "" + a + b + c + d + e + f + g + h + i + j + k + l;

foreach (var item in query)
{
    Console.WriteLine(item);
}

A more advanced answer might be the CartesianProduct