need algorithm name

hello all.. been a few days since i visited "the forums" :)

need some help.

what i would like to do:

-consider an excel sheet. dealing with 5 columns.
-each column has a heading, followed by a bunch of numerical entries
-in the first column i can have 10 possible values, second, 20 possible values, 3rd 5 possible values, 4th 3, and 5th 2 poss values.
-want to write a program to generate all possible combinations of values.

question:
is there a well known algorithm to do this? if so, what is it called? if not, suggestions please.

please do not worry about hooking into excel from c++ etc yet. I have not decided yet whether i will use vba or c++. i'm just looking for an algorithm to do this. also, keep in mind that there is a large number of combinations (which will only get larger in the future- never smaller). there are many other things i have to take into account, so i'm not in the coding phase yet. i just want to see what i can get by way of algorithms so i can plan the rest of the stuff!

i seem to remember from univ courses some sort of good algorithm to do this, but i can't remember! its been a logn time!

thanks!

ps- as much as this sounds like a school assignment, it is not!!!!!!!!!!! i have been done school for a few years!

Don't know if there's a specific algorithm, but it isn't difficult. Just use a series of nested loops.

The outer loop would loop through the values of the first column, with successive inner loops interating the other columns.

thanks for the reply GCDEF.

yes that is true. but i was wondering what the most efficient way to do it is. i might have to do it many times and i might be dealing with a very large number of combinations.

another key thing to note is that this is not a simple truth table. The problem is that the number of possible values for each column are different. so in a normal truth table, you just have 0,1 as the possible entries for each row. here, i might have ten possible values for the entries under column 1, 20 possible values for the entries under col 2 and so on.. i guess your idea of nested loops would work, but i would need five-maybe even more- (and we thought bubble sort was bad :p)

10, 20, 5, 3, 2... This doesn't look to me like a the result of a simple formula (combinations, arithmetic/geomethric series, etc.)

Quote:

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Originally Posted by drewdaman

thanks for the reply GCDEF.

yes that is true. but i was wondering what the most efficient way to do it is. i might have to do it many times and i might be dealing with a very large number of combinations.

another key thing to note is that this is not a simple truth table. The problem is that the number of possible values for each column are different. so in a normal truth table, you just have 0,1 as the possible entries for each row. here, i might have ten possible values for the entries under column 1, 20 possible values for the entries under col 2 and so on.. i guess your idea of nested loops would work, but i would need five-maybe even more- (and we thought bubble sort was bad :p)

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Some problems don't have an effecient solution. I believe this is one of them.

Quote:

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Originally Posted by cilu

10, 20, 5, 3, 2... This doesn't look to me like a the result of a simple formula (combinations, arithmetic/geomethric series, etc.)

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nope.. making a small excel app (have decided now) for some cost, revenue type analysis.

[quote= GCDEF]

Some problems don't have an effecient solution. I believe this is one of them.
[quote]

i guess you're right... i will just do it that way then.

thanks for the replies guys.