Hi, I think I could be able to help, but I need some further information first. What do you mean by the interval between two identical marks? Could you please give another example?

In your example you had these marks

46 37 28 87 76 83 76 38 76 37

The way I see it, the interval between two identical marks is the number of marks which are found between these identical marks. For example in the case of 37, these marks were found: 28 87 76 83 76 38 76, which total a number of 7 as you said. However for 76, they were: 83 and then 38, so each time a total number of 1, as you said. But what would happen in the following situation (considering 76 as identical marks):

76 83 87 76 38 76

In this case the number of marks between two identical marks is not the same. Should we consider the maximum in this case, so the answer for 76 would be 2?

Looking forward to your reply.