HHC 2017 RPN Programming contest information and results thread

[Jeff O.]

Answering my own questions:

(10-01-2017 09:50 PM)Jeff O. Wrote:  ... Maybe I am mistaken, but it seems like there are lots more "Unhappy" than "Happy" numbers. Is this true?

Well, for the numbers 1 through 1000 (calculated using excel, not my program above), 143 are "Happy" and 857 are "Unhappy". So this implies more "Unhappy" results. But my guess is that there are infinite "Happy" and infinite "Unhappy" numbers, and I'm not sure this is a case where one infinity is bigger than another.

(10-01-2017 09:50 PM)Jeff O. Wrote:  Did anyone figure out what the highest number of cycles for a 10 digit or smaller number leading to a "Happy" result is?

I will go out on a limb and postulate that the maximum number of cycles for a 10 or fewer digit number leading to a "Happy" result is 7. I will further postulate that the largest "Happy" number of 10 digits or less requiring 7 cycles is 9,999,999,998, and the smallest such number is 78,999.