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cp9876 wrote: Think of your numbers as little rods
Does that really help you? 
Luc Pattyn [Forum Guidelines] [My Articles]
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No it didn't help me, I added it last thing when I thought my description looked a bit abstract. When I added is I was thinking of cuisenaire rods (link[^]), but others may not know what they are.
Peter
"Until the invention of the computer, the machine gun was the device that enabled humans to make the most mistakes in the smallest amount of time."
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Thank you for bringing up Georges Cuisenaire, a former Belgian teacher;
I vaguely remember having seen, maybe even used, such rods in elementary school,
but nowadays I am pretty sure calculators and computers have eradicated them.
Luc Pattyn [Forum Guidelines] [My Articles]
This month's tips:
- before you ask a question here, search CodeProject, then Google;
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get;
- use PRE tags to preserve formatting when showing multi-line code snippets.
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They didn't help me much at school either, but I did like building things with them. In fact I think that this is probably the first time I have used/referred to them for about 40 years. They're not perfect here, they don't have zero length rods.
Peter
"Until the invention of the computer, the machine gun was the device that enabled humans to make the most mistakes in the smallest amount of time."
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cp9876 wrote: They're not perfect here, they don't have zero length rods
Don't worry, I have an infinite supply ..
I'm largely language agnostic
After a while they all bug me 
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Thanks Peter. You are correct, it turned out to be a standard combinatorial problem as you suggested. It was late and my brain was functioning sub-optimally 
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And if you make the lengths unique, you get a Golomb ruler.
There are II kinds of people in the world, those who understand binary and those who understand Roman numerals. Web - Blog - RSS - Math
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If 'yes' answers to a 'yes'-or-'no' question can be verified "quickly" (in polynomial time), can the answers themselves also be computed quickly?
Richard of York gave battle in vain.
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The answer is: not necessarily. For example, in mathematics there is a class of proofs called "existence proofs" that show an answer exists, but don't give the answer.
Prime factorization comes to mind. We can answer "yes" to the question of whether a large number can be expressed as a product of primes. Computing those primes, however, can be extremely difficult.
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Alan Balkany wrote: Computing those primes, however, can be extremely difficult.
Thankfully, this is very difficult. Our current encryption algorithms depend on it.
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See also the subset-sum problem...
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Hi guys...I am from Bangladesh and my knowledge is very limited.I have developed an algorithm using which any data can be hidden in a text file.After hiding the data in the text file,the size of the text file remains absolutely unchanged and there is no change whatsoever in the file's content as far as reading the file is concerned.I know there r lots of data hiding techniques.Guys can you plse tell me if this techniq has already been implemented the way i have done it...I mean hiding the data in a text file without changing the file size even by a single byte and you wont see a single replacement/change/distortion in any of the letters of the file.As far as reading the file is concerned...the file will remain 100% unchanged even after hiding the data in it.
modified on Tuesday, March 18, 2008 8:42 PM
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Let me get this right. Your algorithm hides data in a file but doesn't alter the file in any way?
Does it look anything like this?
Paul Marfleet
"No, his mind is not for rent
To any God or government"
Tom Sawyer - Rush
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Hiding information in text, isn't that what documentation is about?
Luc Pattyn [Forum Guidelines] [My Articles]
This month's tips:
- before you ask a question here, search CodeProject, then Google;
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get;
- use PRE tags to preserve formatting when showing multi-line code snippets.
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It hides the data in a file and it does not change the file size and no visible change whatsoever in the file.
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Your original post states 'the file will remain 100% unchanged'. If you're not changing the file, how can you be hiding data in it? What you're saying just doesn't make sense.
Paul Marfleet
"No, his mind is not for rent
To any God or government"
Tom Sawyer - Rush
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I said 100% unchanged as far ar reading the file is concerned.
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Pallab_GT wrote: I said 100% unchanged as far ar reading the file is concerned.
How can you make this claim? In order to hide the data, you are going to have to modify some characters in the file. If I use a diff tool to compare the old and new versions of the file, it's going to flag up some differences. If you make changes to a file, they're going to be noticed.
Paul Marfleet
"No, his mind is not for rent
To any God or government"
Tom Sawyer - Rush
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pmarfleet wrote: How can you make this claim? In order to hide the data, you are going to have to modify some characters in the file. If I use a diff tool to compare the old and new versions of the file, it's going to flag up some differences. If you make changes to a file, they're going to be noticed.
You're wrong.
You wrote all the above because you're not aware of occultism superanatural powers.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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You read it wrong.I said AS FAR AS READING THE FILE IS CONCERNED,the file remains 100% unmodified.Ofcourse i have to make some modification but that does not affect the size of the file or for that matter the readability of the file even by a bit.
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Do you know a text file contains just character codes?
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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I know that a text file contains only character codes.And knowing that i am claiming that i can hide data in the text file without replacing/changing/distorting any of the readable letters.
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Pallab_GT wrote: i am claiming that i can hide data in the text file without replacing/changing/distorting any of the readable letters
Then your claim is obviously false. Common sense dictates that data cannot be hidden in a file without requiring the file to be modified. If the file is modified, a diff tool will pick up the changes. If you still believe your claim is true, you are more deluded than I first thought. If you want to perform miracles, maybe you should consider changing careers and become a magician instead of a software developer.
Paul Marfleet
"No, his mind is not for rent
To any God or government"
Tom Sawyer - Rush
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You are missing one point again and again...i am insisting upon the fact that i am not going to change/replace/distort any of the READBLE CHARACTERS.
Before u pass comment u should know that it is not necessary that you will know each and every trick of software development.There might be things beyond ur knowing.One more thing...No body in this world knows everything.
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Pallab_GT wrote: i am not going to change/replace/distort any of the READBLE CHARACTERS
All characters in a text file are readable. That's the whole point; data is stored in text files so it can be read by humans as well as computers. Have a look at the ASCII table[^]. Notice anything? That's right, all the characters are human-readable. Now ask yourself this: if all ASCII characters are readable, what changes can your algorithm make that won't be easily noticed?
Paul Marfleet
"No, his mind is not for rent
To any God or government"
Tom Sawyer - Rush
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