Re^2: Turning very larger numbers into an array of bits

I'm trying to look through every combination of a set that size and find an optimal solution.

2^80 == 1208925819614629174706176. If you could test 1 million per second, your task will take 38 billion (38,308,547,532) years!

Even if you only iterate those 80-bit values that have 7 .. 25 bits set, ~~that is still 304202362464000 variations; and would take over 9 years at 1 million per second.~~

Update: That is still 636,339,175,131,064,539,743 variations (assuming no ordering requirement) which would take 20,164,371 years at 1 million per second.

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Comment on Re^2: Turning very larger numbers into an array of bits

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Re^3: Turning very larger numbers into an array of bits by Marshall (Canon) on Feb 07, 2017 at 19:53 UTC
Yes, BrowserUk you are right... we can go from a super duper wildly humongous number to just a super duper humongous number. There is a heck of a lot that I don't understand about the requirements to this OP. There is presumably some "test" that will be done on these combinations, which the OP does not mention. Whatever that "test" is, it is bound to take some MIPS and probably a significant number of them! Without some more information as to the actual problem that the OP is trying to solve, I do not see any brute force calculation tactics that can do the required math to produce an "optimal solution". I suspect that a better description of the problem could potentially lead to a plausible, "pretty good" rather than an "optimal solution" with many orders less of processing power. Absent that, I am out of ideas.	[reply]

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Re^3: Turning very larger numbers into an array of bits
by Marshall (Canon) on Feb 07, 2017 at 19:53 UTC

BrowserUk

There is presumably some "test" that will be done on these combinations, which the OP does not mention. Whatever that "test" is, it is bound to take some MIPS and probably a significant number of them!

Without some more information as to the actual problem that the OP is trying to solve, I do not see any brute force calculation tactics that can do the required math to produce an "optimal solution". I suspect that a better description of the problem could potentially lead to a plausible, "pretty good" rather than an "optimal solution" with many orders less of processing power. Absent that, I am out of ideas.

[reply]