Hello everybody,
I'm working on a project about permutations which needs to deal with very large integers.
I need to retrieve any permutation of a set with an ID (only to find it, not to save it)
With a small number of possibilites (for ex, with 2^ 3 possibilites, from {1,1,1} to {2,2,2} ) you can easily retrieve {1,1,1} with the ID "0" or {2,2,1} with the ID "3" or {2,2,2} with the ID "7"}, using division, subtraction and modulo operations.
But in my case, I have to deal with something about 30^ 500 000 possibilities. In this case, an ID number can have a length of 650 000 !
That's too much big for an int, even a long.
My question is :
Has anyone worked with integers as large as this ? Is it possible ?
I think yes, but I don't know how to do it.
I just found this post, speaking about java BigIntegers
http://forum.processing.org/topic/every-possible-combination
It looks interesting, but I'm not sure of what it is exactly (creating int as long as I want ?), and I don't know if making operations with integers with a length about 650 000 can be possible without crashing memory or something like that.
Thanks for your help ! :)
I'm working on a project about permutations which needs to deal with very large integers.
I need to retrieve any permutation of a set with an ID (only to find it, not to save it)
With a small number of possibilites (for ex, with 2^ 3 possibilites, from {1,1,1} to {2,2,2} ) you can easily retrieve {1,1,1} with the ID "0" or {2,2,1} with the ID "3" or {2,2,2} with the ID "7"}, using division, subtraction and modulo operations.
But in my case, I have to deal with something about 30^ 500 000 possibilities. In this case, an ID number can have a length of 650 000 !
That's too much big for an int, even a long.
My question is :
Has anyone worked with integers as large as this ? Is it possible ?
I think yes, but I don't know how to do it.
I just found this post, speaking about java BigIntegers
http://forum.processing.org/topic/every-possible-combination
It looks interesting, but I'm not sure of what it is exactly (creating int as long as I want ?), and I don't know if making operations with integers with a length about 650 000 can be possible without crashing memory or something like that.
Thanks for your help ! :)
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