Problem 172
Forum rules
As your posts will be visible to the general public you are requested to be thoughtful in not posting anything that might explicitly give away how to solve a particular problem.
This forum is NOT meant to discuss solution methods for a problem.
See also the topics:
Don't post any spoilers
Comments, questions and clarifications about PE problems.
As your posts will be visible to the general public you are requested to be thoughtful in not posting anything that might explicitly give away how to solve a particular problem.
This forum is NOT meant to discuss solution methods for a problem.
In particular don't post any code fragments or results.
Don't start begging others to give partial answers to problems
Don't ask for hints how to solve a problem
Don't start a new topic for a problem if there already exists one
Don't start begging others to give partial answers to problems
Don't ask for hints how to solve a problem
Don't start a new topic for a problem if there already exists one
See also the topics:
Don't post any spoilers
Comments, questions and clarifications about PE problems.
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mdean
- Posts: 206
- Joined: Tue Aug 02, 2011 2:05 am
Problem 172
I have posted a question in the thread for those who have completed the problem. Sadly, it's at the end of a long post as it wouldn't let me make a new post for just the question. It would be greatly appreciated if someone was able and willing to answer either in that thread or in a private message.

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sivakd
- Posts: 217
- Joined: Fri Jul 17, 2009 9:37 am
- Location: California, USA
- Contact:
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enigmaticcam
- Posts: 16
- Joined: Wed Sep 30, 2015 12:07 am
Re: Problem 172
I have an algorithm that gives me an answer that is not correct. It matches my brute force algorithm up to 9 digits, but the brute force is too slow beyond that. Can anyone confirm these?
xxxx(removed)
Edit: whoops, I realized what my problem was. I was counting all digits up to 18-digit numbers, not just 18-digit numbers.
xxxx(removed)
Edit: whoops, I realized what my problem was. I was counting all digits up to 18-digit numbers, not just 18-digit numbers.
