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Problem 591

Posted: Thu Mar 09, 2017 7:42 pm
by markusmeister
Looking for clarification on the wording of problem 591:
1. "We call BQAd(x,n) the quadratic integer closest to x with the absolute values of a,b not exceeding n." d does not appear in the definition. Is the intended text "We call BQAd(x,n) the quadratic integer of the form a+b*sqrt(d) closest to x with the absolute values of a,b not exceeding n"?
2. "Find the sum of |Id(BQAd(π,10^13))| for all non-square positive integers less than 100." Again d is not defined. Is the intended text "Find the sum of |Id(BQAd(π,10^13))| where d runs through all non-square positive integers less than 100"?

Re: Problem 591

Posted: Thu Mar 09, 2017 8:50 pm
by MHealy
Yes, you have the correct interpretation in both cases.

Re: Problem 591

Posted: Wed Sep 20, 2017 12:28 am
by gh314
My program is correct for all the test cases. I think the problem is that I can't actually verify that the pair I have for √3 is actually the best below 10^13. Does anyone have some more test cases I can run? In the meantime I'll make my own test cases by comparing brute force to my program.

Edit: Solved. I did what I said I would and discovered some inconsistencies in calculated vs brute force with L = 10^6.