problem with functions

[strictly_mk]

Hi all, forgive me if there is a simple solution for this. I am going
through the following piece of code which simply calculates factorials
out of a book, but when i run it I get the answer 0 for whatever number
I input. Can anyone help?

Thanks in advance
strictly_mk

#include "stdio.h"

unsigned long long int return_factoria l(unsigned int num); //function
prototype

int main (void) {

char input[3]; //keyboard input
int number; // number to work with

//prompt user

printf("Enter a positive integer for which the factorial will be
calculated: ");

fgets (input, sizeof(input), stdin); // read the input

sscanf (input, "%d", &number);

//check the input as conditional

if (number > 0) {

printf ("The factorial of %d is %lu.\n", number,
return_factoria l(number));
} else {
printf ("You must enter a positive integer!\n");
}

getchar(); //pause and wait for user

return 0;
}

//This function takes a number and returns its factorial

unsigned long long int return_factoria l(unsigned int num) {

unsigned long long int sum = 1;

unsigned int i; //multiplier to be used in calculating factorial

//Loop through every multiplier up to and including sum

for (sum = 1, i = 1; i <= num; ++i) {

sum *= i;
}

return sum;

} // End of return_factoria l function

[Walter Roberson]

In article <11************ **********@g10g 2000cwb.googleg roups.com>,
<st*********@ho tmail.com> wrote:

Hi all, forgive me if there is a simple solution for this. I am going
through the following piece of code which simply calculates factorials
out of a book, but when i run it I get the answer 0 for whatever number
I input. unsigned long long int return_factoria l(unsigned int num); printf ("The factorial of %d is %lu.\n", number,
return_factori al(number));

return_factoria l returns an unsigned long long, which you then
attempt to print using a format specifier suitable for an
unsigned long. Try using a format specifier of %llu
--
Okay, buzzwords only. Two syllables, tops. -- Laurie Anderson

[strictly_mk]

Thanks, it worked. Thats all it was. Sorry for being a dumbass.

Strictly_mk

[jacob navia]

st*********@hot mail.com a écrit :

Hi all, forgive me if there is a simple solution for this. I am going
through the following piece of code which simply calculates factorials
out of a book, but when i run it I get the answer 0 for whatever number
I input. Can anyone help?

Thanks in advance
strictly_mk

#include "stdio.h"

unsigned long long int return_factoria l(unsigned int num); //function
prototype

int main (void) {

char input[3]; //keyboard input
int number; // number to work with

//prompt user

printf("Enter a positive integer for which the factorial will be
calculated: ");

fgets (input, sizeof(input), stdin); // read the input

sscanf (input, "%d", &number);

//check the input as conditional

if (number > 0) {

printf ("The factorial of %d is %lu.\n", number,
return_factoria l(number));
} else {
printf ("You must enter a positive integer!\n");
}

getchar(); //pause and wait for user

return 0;
}

//This function takes a number and returns its factorial

unsigned long long int return_factoria l(unsigned int num) {

unsigned long long int sum = 1;

unsigned int i; //multiplier to be used in calculating factorial

//Loop through every multiplier up to and including sum

for (sum = 1, i = 1; i <= num; ++i) {

sum *= i;
}

return sum;

} // End of return_factoria l function

If I compile your code with lcc-win32 it will say:

Warning tprintfw.c: 23 printf argument mismatch for format u. Expected
int got unsigned long long

use %llu

[Eric Sosman]

jacob navia wrote On 05/24/06 14:03,:

st*********@hot mail.com a écrit :

unsigned long long int return_factoria l(unsigned int num); //function
prototype

int main (void) {
[...]

printf ("The factorial of %d is %lu.\n", number,
[...]

If I compile your code with lcc-win32 it will say:

Warning tprintfw.c: 23 printf argument mismatch for format u. Expected
int got unsigned long long

That diagnostic seems very confusing to me. Yes, there
is a mismatch between the format and the argument -- but the
message describes a mismatch that isn't there ...

--
Er*********@sun .com

[Flash Gordon]

jacob navia wrote:

st*********@hot mail.com a écrit :
<snip>

unsigned long long int return_factoria l(unsigned int num);
//function
prototype

int main (void) {

char input[3]; //keyboard input
int number; // number to work with
<snip>
printf ("The factorial of %d is %lu.\n", number,
return_factoria l(number));

<snip>
If I compile your code with lcc-win32 it will say:

Warning tprintfw.c: 23 printf argument mismatch for format u. Expected
int got unsigned long long

use %llu

Then you have a rather misleading warning. I see no u format and even if
I did it would expect an unsigned int, not a plain int. I do see an lu
format, but that expects an unsigned long not an int.
--
Flash Gordon, living in interesting times.
Web site - http://home.flash-gordon.me.uk/
comp.lang.c posting guidelines and intro:
http://clc-wiki.net/wiki/Intro_to_clc

[jacob navia]

Eric Sosman a écrit :

jacob navia wrote On 05/24/06 14:03,:

st*********@h otmail.com a écrit :

unsigned long long int return_factoria l(unsigned int num); //function
prototype

int main (void) {
[...]

printf ("The factorial of %d is %lu.\n", number,
[...]

If I compile your code with lcc-win32 it will say:

Warning tprintfw.c: 23 printf argument mismatch for format u. Expected
int got unsigned long long

That diagnostic seems very confusing to me. Yes, there
is a mismatch between the format and the argument -- but the
message describes a mismatch that isn't there ...

I ignore the difference of long/int. If I would not do that, I would
warn when
printf("%lu",3) ;

Obviously in principle you are right, but in practice I try to emit less
warnings so that when there is a warning it doesn't get drowned
in the noise.

Basically when sizeof(effectiv e type) != sizeof(expected type)
there is a warning

[jacob navia]

I ignore the difference of long/int. If I would not do that, I would
warn when
printf("%lu",3) ;

Obviously in principle you are right, but in practice I try to emit less
warnings so that when there is a warning it doesn't get drowned
in the noise.

Basically when sizeof(effectiv e type) != sizeof(expected type)
there is a warning

[Keith Thompson]

jacob navia <ja***@jacob.re mcomp.fr> writes:

I ignore the difference of long/int. If I would not do that, I would
warn when
printf("%lu",3) ;
Which you should.
Obviously in principle you are right, but in practice I try to emit less
warnings so that when there is a warning it doesn't get drowned
in the noise.

Basically when sizeof(effectiv e type) != sizeof(expected type)
there is a warning

Thus you encourage non-portable code.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[Clever Monkey]

jacob navia wrote:

Eric Sosman a écrit :

jacob navia wrote On 05/24/06 14:03,:

st*********@hot mail.com a écrit :

unsigned long long int return_factoria l(unsigned int num);
//function
prototype

int main (void) {
[...]

printf ("The factorial of %d is %lu.\n", number,
[...]

If I compile your code with lcc-win32 it will say:

Warning tprintfw.c: 23 printf argument mismatch for format u.
Expected int got unsigned long long

That diagnostic seems very confusing to me. Yes, there
is a mismatch between the format and the argument -- but the
message describes a mismatch that isn't there ...

I ignore the difference of long/int. If I would not do that, I would
warn when
printf("%lu",3) ;

Obviously in principle you are right, but in practice I try to emit less
warnings so that when there is a warning it doesn't get drowned
in the noise.

Basically when sizeof(effectiv e type) != sizeof(expected type)
there is a warning

If it is not a standard constraint, I guess there is no one saying you
should do any different, but you might consider levels of warning
controlled by switches.