Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,535

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

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

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 have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

Hi;

Where?

**In mathematics, you don't understand things. You just get used to them.I have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

Hi;

Post #17.

**In mathematics, you don't understand things. You just get used to them.I have the result, but I do not yet know how to get it.All physicists, and a good many quite respectable mathematicians are contemptuous about proof.**

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

"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.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

Hi anonimnystefy;

What settings and what answer did you get?

I use:

11

5

Yes

No

see the first drawing in post #17.

I have the result, but I do not yet know how to get it.

All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

11

5

No

No

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

Hi;

That is not the same problem.

I have the result, but I do not yet know how to get it.

All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,535

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

Hi MathsIsFun;

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

I have the result, but I do not yet know how to get it.

All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

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.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

Hi;

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

I have the result, but I do not yet know how to get it.

All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

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.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

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

I have the result, but I do not yet know how to get it.

All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

What permutations?

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

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!

I have the result, but I do not yet know how to get it.

All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

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

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

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

I have the result, but I do not yet know how to get it.

All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

No, when order counts, it is a variation.

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

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.

I have the result, but I do not yet know how to get it.

All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,380

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.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 84,526

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.

I have the result, but I do not yet know how to get it.

All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

Offline