unsigned long long overflow?

[dmpk2k]

Forgive me if this is obvious to you. I feel somewhat foolish.

I've scribbled together something that demonstrates my problem. It takes the
product of all integers n squared, where n is 1..10.

-----------------
int main() {
int i;
unsigned long long product = 1;

for (i=1; i<=10; i++) product *= i * i;

printf("%U\n", product);

return 0;
}
-----------------

Would someone care to inform me why the output is 4114677760 and not
13168189440000? sizeof() tells me that I'm getting a 64-bit variable, so
what's going on? Is it an issue with printf()? And how do I resolve this?
Thanks,

dmpk2k

[Kevin Easton]

dmpk2k <dm******@myahoo.com> wrote:

Forgive me if this is obvious to you. I feel somewhat foolish.

I've scribbled together something that demonstrates my problem. It takes the
product of all integers n squared, where n is 1..10.

-----------------
int main() {
int i;
unsigned long long product = 1;

for (i=1; i<=10; i++) product *= i * i;

printf("%U\n", product);
printf("%llu\n", product);

return 0;
}
-----------------

- Kevin.

[Dan Pop]

In <9X*******************@news04.bloor.is.net.cable.r ogers.com> Tom St Denis <to********@iahu.ca> writes:

dmpk2k wrote:

Forgive me if this is obvious to you. I feel somewhat foolish.

I've scribbled together something that demonstrates my problem. It takes the
product of all integers n squared, where n is 1..10.

-----------------
int main() {
int i;
unsigned long long product = 1;

for (i=1; i<=10; i++) product *= i * i;

printf("%U\n", product);

%U is wrong for long long

%U is wrong for *anything*, being plain undefined behaviour.

Dan
--
Dan Pop
DESY Zeuthen, RZ group
Email: Da*****@ifh.de

[Emmanuel Delahaye]

In 'comp.lang.c', dmpk2k <dm******@Myahoo.com> wrote:

int main() {
int i;
unsigned long long product = 1;

for (i=1; i<=10; i++) product *= i * i;

printf("%U\n", product);
You want "%llu"
return 0;
}

--
-ed- em**********@noos.fr [remove YOURBRA before answering me]
The C-language FAQ: http://www.eskimo.com/~scs/C-faq/top.html
<blank line>
FAQ de f.c.l.c : http://www.isty-info.uvsq.fr/~rumeau/fclc/

[Dan Pop]

In <Xn**************************@130.133.1.4> Emmanuel Delahaye <em**********@noos.fr> writes:

In 'comp.lang.c', dmpk2k <dm******@Myahoo.com> wrote:

int main() {
int i;
unsigned long long product = 1;

for (i=1; i<=10; i++) product *= i * i;

printf("%U\n", product);

You want "%llu"

Unless he has a conforming C99 implementation, there is no way of telling
what he really needs.

Dan
--
Dan Pop
DESY Zeuthen, RZ group
Email: Da*****@ifh.de

[Bill Hanna]

Da*****@cern.ch (Dan Pop) wrote in message news:<be**********@sunnews.cern.ch>...

In <Xn**************************@130.133.1.4> Emmanuel Delahaye <em**********@noos.fr> writes:

In 'comp.lang.c', dmpk2k <dm******@Myahoo.com> wrote:

int main() {
int i;
unsigned long long product = 1;

for (i=1; i<=10; i++) product *= i * i;

printf("%U\n", product);

You want "%llu"

Unless he has a conforming C99 implementation, there is no way of telling
what he really needs.
Dan

MS Visual C++ and Bloodshed C++ have a bug in the ostream program
that limits the output to 32 Bits when using printf. It will only
output the lower half of the long long data. MS has listed a
work-around fix on their website. I have tried to use their
recommendation but it does not work. MS states that the bug will be
fixed in Visual C.net.
Bill Hanna

[Bill Hanna]

Da*****@cern.ch (Dan Pop) wrote in message news:<be**********@sunnews.cern.ch>...

In <Xn**************************@130.133.1.4> Emmanuel Delahaye <em**********@noos.fr> writes:

In 'comp.lang.c', dmpk2k <dm******@Myahoo.com> wrote:

int main() {
int i;
unsigned long long product = 1;

for (i=1; i<=10; i++) product *= i * i;

printf("%U\n", product);

You want "%llu"

Unless he has a conforming C99 implementation, there is no way of telling
what he really needs.

Dan

Use "%I64d" or "%I64u" or "%I64x". This works on Bloodshed C++.
I found the info from an old posting in 2001.

Bill Hanna

[Emmanuel Delahaye]

In 'comp.lang.c', bi*****@aol.com (Bill Hanna) wrote:

Use "%I64d" or "%I64u" or "%I64x". This works on Bloodshed C++.
I found the info from an old posting in 2001.

The Dev-C++ IDE 4.x by Bloodshed uses gcc 3.2.x. It supports C99 'long long'
and "%llu".

--
-ed- em**********@noos.fr [remove YOURBRA before answering me]
The C-language FAQ: http://www.eskimo.com/~scs/C-faq/top.html
<blank line>
FAQ de f.c.l.c : http://www.isty-info.uvsq.fr/~rumeau/fclc/