Format a Large Number [duplicate] - c

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Closed 11 years ago.
Possible Duplicate:
How to format a number from 1123456789 to 1,123,456,789 in C?
How can I format a large integral number with commas in C, such that the readability is improved?
222222 should be 222,222 and 44444444 should be 44,444,444.

You do not need to do the formatting yourself; printf in Unix has a ' modifier:
printf("%'d\n", number);
It looks like Visual Studio doesn't support that. This syntax is locale-aware, however.

Use the modulus (%) operation and build your own string.

If you google for "c format thousands separator" then one of the hits is this page http://www.codeguru.com/forum/archive/index.php/t-402370.html
It's C++ though but it should give you an idea of what you can do.

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Using a dot for variable declaration in C [duplicate]

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What is the meaning of a dot (.) after an integer in c?
(2 answers)
Closed 2 years ago.
I read a code online and the next line caught my attention since I don't know why does it have a "." after the 0:
variable=0.;
I couldn't find the answer after looking for it. Could you please tell me what is the dot for?
Thanks!!
The dot makes it a double. A clearer way to write it is 0.0.

Which one is prefered %i or %d [duplicate]

This question already has answers here:
What is the difference between conversion specifiers %i and %d in formatted IO functions (*printf / *scanf)
(4 answers)
Closed 6 years ago.
Just started learning c. And I noticed that there are 2 format specifiers for int.
%i
%d
I like to use %i (The i of integer). But I see most people use %d. Is there like a rule or something (like you have rules for variable naming (camelCase or underscores etc.)).
I allready noticed this question but it did not really help.
But this is not my question. My question was which one is more commonly used. And which one should I pick. My question is not wat is the difference.
If you look good at these questions you see that in the other question there is nothing about which one is more commonly used they just say it is interchangeble.
Is it just so that you can choose. Is one of them more common to use or recommanded?
They are the same. Use whichever one you like. One stands for "integer" and the other stands for "decimal".
At a guess, there are two from early, conflicting implementations. And I'm talking like half a century ago.
I use %d and, to be honest, I haven't the faintest idea why.
They mean different things for scanf, though!

Datatype which can store very large value in C [duplicate]

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Are there any solid large integer implementations in C? [closed]
(7 answers)
Closed 8 years ago.
Recently in programming contest in Here, the problem is pretty straight forward but catch is with worst case scenario which we have to handle data of size 10^10000 .
I tried the program in python which is straight forward as i don't have to specify the datatype(It is taken care by the compiler ) but when i tried with C I couldn't find the correct datatype .
(I tried uintmax_t which didn't work out too).
So how to approach very huge type of data's in C ?
There is no built-in datatype in C that can store that big values. You will either have to write your own implementation or use a library. As this is a competition, though the second is not an option. Every now and then similar problems appear and usually the best approach is to use another language e.g. java(as it is usually available on competitions).

How to get date in a particular format [duplicate]

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How to format date and time string in C++
(6 answers)
How to print time in format: 2009‐08‐10 18:17:54.811
(7 answers)
Closed 9 years ago.
I have been searching on the net on how to get and store the current date in yyyymmdd format. There are many code out there but it formats the dos %date%:%time% output to required specs.
The problem with that is, I need it to work universally across all regional settings. I can't find the code example to do that.
Can anyone help? If this is not possible, then is there a way to change the regional setting temporarily write the file and change it back to what it was?

How is the function "sin" realized? [duplicate]

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How does C compute sin() and other math functions?
(22 answers)
Closed 9 years ago.
Anybody can explain or show how is the function "sin" (or "sinf", "sinl") realized in C.
Intuition suggests that it should be somewhere in the math.h but I did not see anything there
There's a couple ways I can think of right off the bat:
Lookup tables
Approximation via Taylor series (which can be easily made accurate to a number of significant digits).

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