Long numer data type

[nagu89]

hello. Ive been using a pretty long number in my program . its problem3 of the euler project . Its 600851475143 . What data type do I use for this???

[jephthah]

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[jephthah]

a "long long" data type is a 64 bit number, and gives

Signed min: -9223372036854775808
Signed max: 9223372036854775807
Unsigned max: 18446744073709551615

.

[Dave Sinkula]

http://projecteuler.net/index.php?section=problems

[nagu89]

a "long long" data type is a 64 bit number, and gives

Signed min: -9223372036854775808 Signed max: 9223372036854775807 Unsigned max: 18446744073709551615

.

Thank you>>>And what is the format spec?Im working on devC++

[jephthah]

the format specifier for a long long int is

long long myBigNum=600851475143;

printf("the number is:  %lld\n",myBigNum);

.

[nagu89]

the format specifier for a long long int is

long long myBigNum=600851475143;

printf("the number is:  %lld\n",myBigNum);

.

Thank you

[nagu89]

Thank you

[IMG]http://img8.imageshack.us/my.php?image=devsnap.png[/IMG]
Im still not able to get the precision required

[s_sridhar]

If you want to use numbers of very huge sizes i bet strings might be useful. You must perhaps use several functions for performing those operations. for eg. when you add two strings, proceed from the last digit and carry over the excess to the next digit and so on.

[jephthah]

[IMG]http://img8.imageshack.us/my.php?image=devsnap.png[/IMG] Im still not able to get the precision required

i dont know why not.

i'm using GCC v3.4, which is over 3 years old.

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    unsigned long long bignum = 600851475143 ;

    printf("bignum    : %lld\n",bignum);
    printf("bignum * 2: %lld\n",bignum * 2);
    printf("bignum * 4: %lld\n",bignum * 4);
    return 0;
}

gives the following result:

bignum    : 600851475143
bignum * 2: 1201702950286
bignum * 4: 2403405900572

Process returned 0 (0x0)   execution time : 0.050 s
Press any key to continue.

you're either doing something wrong, or your compiler sucks or something.

[s_sridhar]

Can you tell me, why is it wrong?? You can very well use atoi function. for converting characters to numbers

[s_sridhar]

>Jepthah Without knowing how it works, it is bad to comment. Well you know operator overloading???? and you can very well stop being rude.

[jephthah]

Can you tell me, why is it wrong?? You can very well use atoi function. for converting characters to numbers

beat it, kid. your answer isn't just wrong, it's completely irrelevant.

[s_sridhar]

Well, it's not irrelevant. Strings can be configured to handle large numbers.

[nagu89]

Well, it's not irrelevant. Strings can be configured to handle large numbers.

Will both you guys please stop fighting and try helping me out?
I got so frustrated over the issue and did it in PYTHON. But Yes , there is a wqay of using srings to handle large integers but I guess my compiler is the culprit. Guys. - Let me know of a decent compiler and where to download it

[s_sridhar]

I don't think downloading a compiler will help. You must write those functions.

[nagu89]

I don't think downloading a compiler will help. You must write those functions.

It seems to be working perfectly for you. what compiler or IDE are you using?

[s_sridhar]

What i meant was we can't directly use those functions and we must write those, i meant it is not compiler based but user based. if you want i'll send those codes

[nagu89]

ok. please do

[jephthah]

I got so frustrated over the issue and did it in PYTHON. But Yes , there is a wqay of using srings to handle large integers but I guess my compiler is the culprit. Guys. - Let me know of a decent compiler and where to download it

there absolutely is a way to do it with 64-bit integers. C99 standard defines the 64-bit integer as the long long int data type.

i do not have any problem using this data type with my compiler, GCC version 3.4. I believe GCC current version is up to 4.3.

apparently, although i have not verified this personally, Windows and Borland compilers define the long long int as __int64 ... http://home.att.net/~jackklein/c/inttypes.html#long_long

now you can either listen to some clown who wants you to create a string-based big integer handler from scratch, or you can use the 64-bit integer data type that is defined in the C99 standard. your current compiler may not adhere to this standard, but there are plenty that do.

http://www.codeblocks.org/
http://gcc.gnu.org/
http://www.mingw.org/

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