hi.. i want to find all the possible combinations of 8 characters including letters and numbers.
The letters should be all capitalized and the combination should be letters and numbers alternately.
This are the examples:
C8L8J1A4
A7C8H2I4
Q8F9H6D9
Q1A9C8J9
Well a macro to do it would produce 5.3 billion rows/cells so..
kala1928: how do you arrive at that?
27 letters x 10 numbers x 27 letters x 10 numbers etc?Originally Posted by StephenR
if the point is to actually 'see' each unique combination
could you please teach me how to come up with the possible combinations... i don't care if it takes billions but i really need to know.. please help me and tell me the exact formula... thanks.
OK I'd interpreted it differently, but I see what you mean. How many versions of Excel before it can handle 5 billion cells?
The OP needs to clarify his/her requirements.
EDIT: that's not really an Excel question. http://en.wikipedia.org/wiki/Combination
Last edited by StephenR; 09-08-2010 at 07:50 AM.
There will be 36^8 combinations - each character can have any one of 36 values (A-Z and 0-9), so with no restraints there will be 2.8 trillion(US) combinations. They could be written to a text file, but if each row takes 8 bytes the final file will be in the region of 20Tb and if your code can generate and write 1,000 combinations per second it will take around 90 years to run (not accounting for Moore's law).
On the other hand the code to actually generate the file is trivial, but testing it may take a while
Edited to add: Sorry, missed the requirement to alternate between letters and numbers, that pulls the combinations down to 4.6 billion and the file size to a mere 34Gb. (Or, if the sequence can also be number, letter, number, letter then there will be 9.1Bn combinations)
Last edited by Andrew-R; 09-08-2010 at 07:56 AM.
Now this would be right if you wanted to see how many combinations there are if you are only allowed to use 8 numbers and 8 different letters. See what you did wrong there?
Or does the OP mean permutations of "C8L8J1A4"? The suspense is not quite killing me.
yes
for any four for 26 letter 456976 combination
for any four of 10 numbers 1000
the combination of both
is more than 5 billon trillon zillon
Any one of 26 letters in odd positions = 26^4 = 456,976 permutations
Any one of 10 digits in even positions = 10^4 = 10,000 permutations
Total permutations = 4,569,760,000, as Andrew said.
grifter_1229, what would you do with this list that you couldn't do without it?
Entia non sunt multiplicanda sine necessitate
To do this you would need a lot of nested for loops.
You'd probably want
for (each letter in alphabet)
for (each number 0 - 9)
for (each letter in alphabet)
....
put all variables together and put into a cell and move down a cell... repeat
And this would be 4.6B combinations. the formula above is correct.
what's a billon trillon zillon?
CC
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I'm guessing it must be about the same number of times people have said there are 4.6 billion combinations...
Is it bigger than a googolplex ? That's a loop I'd like to see...
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Really? Oh well, here you go, just in case you need to know the factorial of a googolplex.
Do let me know if it works properly.
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Could I have a Progress Bar with that please ?
(perhaps in the form of Hangman)
Your wish, etc ... coded to Microsoft standards.
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Andrew - I'm getting an error on the first line?
http://xkcd.com/207/
Always entertains
ha ha - that's brilliant - I love the next one on Regular Expressions...
(hijack over)
I think we should continue with the hijack. I'd imagine that by now the OP has constructed their nested loop routine and needs some light reading to occupy them while it runs.
Yes, I've done all of the hard work, so I left defining the variable classes as an exercise for the reader.
Charlie... did you see comic 292????
http://xkcd.com/292/
I'm glad everyone else has left the office, I laughed like a drain.
Last edited by Cheeky Charlie; 09-15-2010 at 07:51 AM. Reason: interesting approach to English
Sorry guys but your googolplex loop is going to get an error (not enough mass) at some point.
You see, there isn't enough mass in the universe to actually print all the zeroes in decimal format.
Sheesh, do I have to do *everything* for you guys?
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Last edited by Andrew-R; 09-15-2010 at 09:06 AM.
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