I have a little program I'm working on for my project (a simple practice in school), part of the program is that it should receive input composed of an array of 7 digit (or less) numbers which should contain only distinct digits and of course process of generating those numbers is a bit too slow and it's a bit frustrating since it's not even a main function. I was able too speed things up by using parallel computing yet I wonder if there is any way other than trying to evaluate each consecutive sequence of numbers to determine if it contains any digit more than once?
I tried looking through internet for some similar problem or algorithm but found nothing helpful.