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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,552

It may simply have run out of time ... I know it took a while on my PC.

Try a slightly smaller one and see if it works

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

Hi MIF

It works for a,a,b,c,d. But, functioning for inputs smaller than 10 input characters isn't very practical. Maybe you can use some other method for calculating their number (using e.g. a script written in a mathematical package).

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

Hi MIF;

It may simply have run out of time ... I know it took a while on my PC.

Yes, it takes some time on mine too. It seems to be working fine for smaller ones.

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

What input did you take, bobbym?

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

Hi;

Where?

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

bobbym wrote:

Yes, it takes some time on mine too.

What did you enter as an input (which letters) that gave the slow output?

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

Hi;

Post #17.

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

"m,a,t,h,e,m,a,t,i,c,s"? I get the results pretty fast for that one.

Here lies the reader who will never open this book. He is forever dead.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

Hi anonimnystefy;

What settings and what answer did you get?

I use:

11

5

Yes

No

see the first drawing in post #17.

**In mathematics, you don't understand things. You just get used to them.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

11

5

No

No

Here lies the reader who will never open this book. He is forever dead.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

Hi;

That is not the same problem.

**In mathematics, you don't understand things. You just get used to them.**

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,552

The calculations are done on your own PC, so results may vary.

And so it is hard for me to write a program that will finish within the "timeout" that is imposed by Flash.

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

Hi MathsIsFun;

No problem. It works for the smaller problems that I have tried on it so far.

**In mathematics, you don't understand things. You just get used to them.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

Hi bobbym

You are right. It takes much more time and it comes out empty.

Hi MIF

I would suggest that for very large output (more than 10^7 possibilities), you do not show the whole output, just the number of possibilities.

Here lies the reader who will never open this book. He is forever dead.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

Hi;

10^7 is a little bit too large. The above problem only has 13000 permutations. Maybe 10^5 is better.

**In mathematics, you don't understand things. You just get used to them.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

Either way, it should skip the printing when the number is large.

How did you calculate the number of the possible combinations?

Here lies the reader who will never open this book. He is forever dead.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

I didn't. I counted the number of permutations.

**In mathematics, you don't understand things. You just get used to them.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

What permutations?

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

The problem in post #17 is a permutation.

As you were taught, you try not to work on a problem that you do not already know the answer to. Remember back engineering? You work from the answer to the question, filling in the details.

Normally to do that I would have just counted them up first. But here MIF already does that with his program so you should use what to get the answer?

GF's of course!

**In mathematics, you don't understand things. You just get used to them.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

When you choose a number of objects out of a larger set of objects, those can be only combinations or variations, not permutations.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

Did you look at post #17? When order counts we are talking about a permutation.

**In mathematics, you don't understand things. You just get used to them.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

No, when order counts, it is a variation.

Here lies the reader who will never open this book. He is forever dead.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

Hi;

http://www.askamathematician.com/2010/0 … nt-matter/

You will notice that in this exact type of problem he calls it an arrangement or permutation.

Anyways, it is calculated in the same way.

**In mathematics, you don't understand things. You just get used to them.**

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,658

Just because he calls it that, doesn't mean it should be called that way.

I can't seem to calculate those using GFs.

Here lies the reader who will never open this book. He is forever dead.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,678

http://en.wikipedia.org/wiki/Permutatio … binatorics

Post #17 is similar to a mississippi problem, which is definitely a permutation.

I can't seem to calculate those using GFs.

Well of course you can not if you call it a variation. There are ogf's for combinations and egf's for permutations.

**In mathematics, you don't understand things. You just get used to them.**

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