[Tutor] Set changing order of items?

[Kent Johnson]

Adam Cripps wrote:
> Many thanks all - I've got there in the end, using a tuple inside a
> set, ditching the question number and then rendering the sum for
> output in my main gui module.
> 
> However, this does raise another issue now (which I had thought would
> happen, but was putting it off until I'd solved the original problem).
> 
> Basically, the user can choose how many problems are set - i. They can
> also choose the highest and lowest possible numbers - highest and
> lowest. With these values, they can now create a scenario which will
> lock the application - they can choose values with a narrow margin
> (lowest = 5, highest = 6) and then choose to have 100 of these
> problems (i=100). Of course, this will mean that my app will now go
> through that loop trying to find a new combination that no longer is
> possible.

This is a pretty easy condition to test for - maybe check that the 
number of possible problems in the given range is at least double (or 
some multiple) of the number of problems desired. If not, print an error 
message and have them enter new values.
> 
> Anyone have any guidance or tips here? How will I create a flag which
> is raised once the loop becomes infinite?

You could also restrict the loop to, say, twice the number of problems 
desired and give up if after that many loops you don't have the desired 
number.

Kent