Same program in C and in C#. C# is faster than C. How Come ?

[c]

Hi every one,

Me and my Cousin were talking about C and C#, I love C and he loves
C#..and were talking C is ...blah blah...C# is Blah Blah ...etc

and then we decided to write a program that will calculate the
factorial of 10, 10 millions time and print the reusult in a file with
the name log.txt..

I wrote something like this

#include <stdio.h>
unsigned int fib (int n);

int main()
{
FILE *fp;
unsigned int loop =1 ;
if ( (fp = fopen( "log.txt", "a" )) != NULL )
for (loop; loop <= 10000000 ; loop++)
{

fprintf(fp,"%u\ n",fib(10));
}
fclose (fp);
return 0;
}

unsigned int fib (int n)
{ if (n != 1 )
return n * fib(n-1);
else
return 1;
}
and he did the something in C#
and then we all have the same laptop..DELL Inspiron 6000.

I ran my program, I took 18 seconds to get done..his program took 7
seconds..Wow

and then I asked him to run my program in his laptop..it's all the
same ..but I wanted to...I ran it...gave me the same time..

How come ..?!

Next day, I tried some Optimization

and developed the loop and wrote something like this

for (loop; loop <= 1000000 ; loop++)
{
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
}

But his program still faster than mine..

then, I tried the program under Slackware 12....it took 3.8 Seconds to
get done..Wow, I won the Challenge..

anyway, he want me to beat him under windows XP...Please guys help me
out..

[Richard Tobin]

In article <da************ *************** *******@c4g2000 hsg.googlegroup s.com>,
c <al******@gmail .comwrote:

>unsigned int fib (int n)
{ if (n != 1 )
return n * fib(n-1);
else
return 1;
}

I think "fact" would be a better name for this function.

>and then we all have the same laptop..DELL Inspiron 6000.

I ran my program, I took 18 seconds to get done

What compiler did you use? What optimisation settings? You can't
tell much about the relative advantages of the languages just from a
random figure like that.

>and developed the loop and wrote something like this

for (loop; loop <= 1000000 ; loop++)
{
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib( 10),fib(10),fib (10),fib(10));
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib( 10),fib(10),fib (10),fib(10));
}

This is likely to be a pointless change. The loop overhead is small
compared with time taken for the factorial function.

Most likely your program would be significantly faster if you used
a loop to calculate the factorial rather than recursion.

-- Richard
--
:wq

[c]

On Dec 13, 2:35 am, rich...@cogsci. ed.ac.uk (Richard Tobin) wrote:

In article <da48736e-99f7-495f-90d8-627d34845...@c4 g2000hsg.google groups.com>,

c <alcon...@gmail .comwrote:

unsigned int fib (int n)
{ if (n != 1 )
return n * fib(n-1);
else
return 1;
}

I think "fact" would be a better name for this function.

and then we all have the same laptop..DELL Inspiron 6000.

I ran my program, I took 18 seconds to get done

What compiler did you use? What optimisation settings? You can't
tell much about the relative advantages of the languages just from a
random figure like that.

and developed the loop and wrote something like this

for (loop; loop <= 1000000 ; loop++)
{
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
}

This is likely to be a pointless change. The loop overhead is small
compared with time taken for the factorial function.

Most likely your program would be significantly faster if you used
a loop to calculate the factorial rather than recursion.

-- Richard
--
:wq

I tried Tiny C Compiler, and with Turbo C...
we both (me and my cousin) used recursion in our programs.
Than you .

[c]

On Dec 13, 2:41 am, c <alcon...@gmail .comwrote:

On Dec 13, 2:35 am, rich...@cogsci. ed.ac.uk (Richard Tobin) wrote:

In article <da48736e-99f7-495f-90d8-627d34845...@c4 g2000hsg.google groups.com>,

c <alcon...@gmail .comwrote:

>unsigned int fib (int n)
{ if (n != 1 )
return n * fib(n-1);
else
return 1;
}

I think "fact" would be a better name for this function.

>and then we all have the same laptop..DELL Inspiron 6000.

>I ran my program, I took 18 seconds to get done

What compiler did you use? What optimisation settings? You can't
tell much about the relative advantages of the languages just from a
random figure like that.

>and developed the loop and wrote something like this

for (loop; loop <= 1000000 ; loop++)
{
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
>",fib(10),fib( 10),fib(10),fib (10),fib(10));
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
>",fib(10),fib( 10),fib(10),fib (10),fib(10));
}

This is likely to be a pointless change. The loop overhead is small
compared with time taken for the factorial function.

Most likely your program would be significantly faster if you used
a loop to calculate the factorial rather than recursion.

-- Richard
--
:wq

I tried Tiny C Compiler, and with Turbo C...
we both (me and my cousin) used recursion in our programs.

Than you .

One more thing, Why under Slackware with GCC..my program goes faster ?
I test it with time

[slackware] time ./fact

[Francine.Neary]

On Dec 12, 11:45 pm, c <alcon...@gmail .comwrote:

On Dec 13, 2:41 am, c <alcon...@gmail .comwrote:

On Dec 13, 2:35 am, rich...@cogsci. ed.ac.uk (Richard Tobin) wrote:

In article <da48736e-99f7-495f-90d8-627d34845...@c4 g2000hsg.google groups.com>,

c <alcon...@gmail .comwrote:
unsigned int fib (int n)
{ if (n != 1 )
return n * fib(n-1);
else
return 1;
}

I think "fact" would be a better name for this function.

and then we all have the same laptop..DELL Inspiron 6000.

I ran my program, I took 18 seconds to get done

What compiler did you use? What optimisation settings? You can't
tell much about the relative advantages of the languages just from a
random figure like that.

and developed the loop and wrote something like this

for (loop; loop <= 1000000 ; loop++)
{
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
}

This is likely to be a pointless change. The loop overhead is small
compared with time taken for the factorial function.

Most likely your program would be significantly faster if you used
a loop to calculate the factorial rather than recursion.

-- Richard
--
:wq

I tried Tiny C Compiler, and with Turbo C...
we both (me and my cousin) used recursion in our programs.

Than you .

One more thing, Why under Slackware with GCC..my program goes faster ?
I test it with time

[slackware] time ./fact

The answer to your question is 42.

[user923005]

On Dec 12, 3:23 pm, c <alcon...@gmail .comwrote:

Hi every one,

Me and my Cousin were talking about C and C#, I love C and he loves
C#..and were talking C is ...blah blah...C# is Blah Blah ...etc

and then we decided to write a program that will calculate the
factorial of 10, 10 millions time and print the reusult in a file with
the name log.txt..

I wrote something like this

#include <stdio.h>
unsigned int fib (int n);

int main()
{
FILE *fp;
unsigned int loop =1 ;
if ( (fp = fopen( "log.txt", "a" )) != NULL )
for (loop; loop <= 10000000 ; loop++)
{

fprintf(fp,"%u\ n",fib(10));
}
fclose (fp);
return 0;

}

unsigned int fib (int n)
{ if (n != 1 )
return n * fib(n-1);
else
return 1;
}

and he did the something in C#

and then we all have the same laptop..DELL Inspiron 6000.

I ran my program, I took 18 seconds to get done..his program took 7
seconds..Wow

and then I asked him to run my program in his laptop..it's all the
same ..but I wanted to...I ran it...gave me the same time..

How come ..?!

Next day, I tried some Optimization

and developed the loop and wrote something like this

for (loop; loop <= 1000000 ; loop++)
{
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
}

But his program still faster than mine..

then, I tried the program under Slackware 12....it took 3.8 Seconds to
get done..Wow, I won the Challenge..

anyway, he want me to beat him under windows XP...Please guys help me
out..

The recursive factorial function will be a lot slower than an
iterative one.
But the lion's share of the time is going to be in writing out the
text file.
It occupies 160 MB on my machine. It appears that your friend has a
faster disk than you do.
This might be marginally faster:

#include <stdio.h>

unsigned fact(unsigned n)
{
unsigned result = 1;
while (n-- 1)
result *= n;
return result;
}

int main()
{
FILE *fp;
unsigned loop;
if ((fp = fopen("log.txt" , "a")) != NULL) {
setvbuf(fp, NULL, _IOFBF, 16000);
for (loop=1; loop <= 10000000; loop++) {
fprintf(fp, "%u\n", fact(10));
}
fclose(fp);
}
return 0;
}

This program executes in less than one second on my machine (showing
that the time is almost exclusively I/O):

#include <stdio.h>

unsigned fact(unsigned n)
{
unsigned result = 1;
while (n-- 1)
result *= n;
return result;
}

int main()
{
FILE *fp;
unsigned loop;
double sum = 0;
if ((fp = fopen("log.txt" , "a")) != NULL) {
setvbuf(fp, NULL, _IOFBF, 16000);
for (loop=1; loop <= 10000000; loop++) {
sum += fact(10);
}
printf("sum was %f\n", sum);
fclose(fp);
}
return 0;
}
/*
C:\tmp>foo
sum was 3628800000000.0 00000
*/

[c]

On Dec 13, 2:54 am, user923005 <dcor...@connx. comwrote:

On Dec 12, 3:23 pm, c <alcon...@gmail .comwrote:

Hi every one,

Me and my Cousin were talking about C and C#, I love C and he loves
C#..and were talking C is ...blah blah...C# is Blah Blah ...etc

and then we decided to write a program that will calculate the
factorial of 10, 10 millions time and print the reusult in a file with
the name log.txt..

I wrote something like this

#include <stdio.h>
unsigned int fib (int n);

int main()
{
FILE *fp;
unsigned int loop =1 ;
if ( (fp = fopen( "log.txt", "a" )) != NULL )
for (loop; loop <= 10000000 ; loop++)
{

fprintf(fp,"%u\ n",fib(10));
}
fclose (fp);
return 0;

}

unsigned int fib (int n)
{ if (n != 1 )
return n * fib(n-1);
else
return 1;
}

and he did the something in C#

and then we all have the same laptop..DELL Inspiron 6000.

I ran my program, I took 18 seconds to get done..his program took 7
seconds..Wow

and then I asked him to run my program in his laptop..it's all the
same ..but I wanted to...I ran it...gave me the same time..

How come ..?!

Next day, I tried some Optimization

and developed the loop and wrote something like this

for (loop; loop <= 1000000 ; loop++)
{
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
}

But his program still faster than mine..

then, I tried the program under Slackware 12....it took 3.8 Seconds to
get done..Wow, I won the Challenge..

anyway, he want me to beat him under windows XP...Please guys help me
out..

The recursive factorial function will be a lot slower than an
iterative one.
But the lion's share of the time is going to be in writing out the
text file.
It occupies 160 MB on my machine. It appears that your friend has a
faster disk than you do.
This might be marginally faster:

#include <stdio.h>

unsigned fact(unsigned n)
{
unsigned result = 1;
while (n-- 1)
result *= n;
return result;

}

int main()
{
FILE *fp;
unsigned loop;
if ((fp = fopen("log.txt" , "a")) != NULL) {
setvbuf(fp, NULL, _IOFBF, 16000);
for (loop=1; loop <= 10000000; loop++) {
fprintf(fp, "%u\n", fact(10));
}
fclose(fp);
}
return 0;

}

This program executes in less than one second on my machine (showing
that the time is almost exclusively I/O):

#include <stdio.h>

unsigned fact(unsigned n)
{
unsigned result = 1;
while (n-- 1)
result *= n;
return result;

}

int main()
{
FILE *fp;
unsigned loop;
double sum = 0;
if ((fp = fopen("log.txt" , "a")) != NULL) {
setvbuf(fp, NULL, _IOFBF, 16000);
for (loop=1; loop <= 10000000; loop++) {
sum += fact(10);
}
printf("sum was %f\n", sum);
fclose(fp);
}
return 0;}

/*
C:\tmp>foo
sum was 3628800000000.0 00000
*/

Thanks sir for you reply..
you mentioned "It appears that your friend has a
faster disk than you do"
We both have the same laptop..same model..anyway, I tested my program
in his laptop just in case..
anyway, I compiled the code you posted..its save a 0-byte text file on
machine..
I will try with another compiler..I'll get back to you..

[c]

On Dec 13, 2:51 am, Francine.Ne...@ googlemail.com wrote:

On Dec 12, 11:45 pm, c <alcon...@gmail .comwrote:

On Dec 13, 2:41 am, c <alcon...@gmail .comwrote:

On Dec 13, 2:35 am, rich...@cogsci. ed.ac.uk (Richard Tobin) wrote:

In article <da48736e-99f7-495f-90d8-627d34845...@c4 g2000hsg.google groups.com>,

c <alcon...@gmail .comwrote:
>unsigned int fib (int n)
{ if (n != 1 )
return n * fib(n-1);
else
return 1;
}

I think "fact" would be a better name for this function.

>and then we all have the same laptop..DELL Inspiron 6000.

>I ran my program, I took 18 seconds to get done

What compiler did you use? What optimisation settings? You can't
tell much about the relative advantages of the languages just from a
random figure like that.

>and developed the loop and wrote something like this

for (loop; loop <= 1000000 ; loop++)
{
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
>",fib(10),fib( 10),fib(10),fib (10),fib(10));
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
>",fib(10),fib( 10),fib(10),fib (10),fib(10));
}

This is likely to be a pointless change. The loop overhead is small
compared with time taken for the factorial function.

Most likely your program would be significantly faster if you used
a loop to calculate the factorial rather than recursion.

-- Richard
--
:wq

I tried Tiny C Compiler, and with Turbo C...
we both (me and my cousin) used recursion in our programs.

Than you .

One more thing, Why under Slackware with GCC..my program goes faster ?
I test it with time

[slackware] time ./fact

The answer to your question is 42.

What do you mean by 42..please give me more details..

[pete]

c wrote:

>
Hi every one,

Me and my Cousin were talking about C and C#, I love C and he loves
C#..and were talking C is ...blah blah...C# is Blah Blah ...etc

and then we decided to write a program that will calculate the
factorial of 10, 10 millions time and print the reusult in a file with
the name log.txt..

I wrote something like this

#include <stdio.h>
unsigned int fib (int n);

int main()
{
FILE *fp;
unsigned int loop =1 ;
if ( (fp = fopen( "log.txt", "a" )) != NULL )
for (loop; loop <= 10000000 ; loop++)
{

fprintf(fp,"%u\ n",fib(10));
}
fclose (fp);
return 0;
}

unsigned int fib (int n)
{ if (n != 1 )
return n * fib(n-1);
else
return 1;
}

and he did the something in C#

and then we all have the same laptop..DELL Inspiron 6000.

I ran my program, I took 18 seconds to get done..his program took 7
seconds..Wow

and then I asked him to run my program in his laptop..it's all the
same ..but I wanted to...I ran it...gave me the same time..

How come ..?!

Next day, I tried some Optimization

and developed the loop and wrote something like this

for (loop; loop <= 1000000 ; loop++)
{
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
}

But his program still faster than mine..

then, I tried the program under Slackware 12....it took 3.8 Seconds to
get done..Wow, I won the Challenge..

anyway, he want me to beat him under windows XP...Please guys help me
out..

My first guess is that fprintf is your slowest dog.
The second most obvious improvement would be to
remove recursion from your fib function.

Your program runs in 19 cursor blinks on my machine.
My program, new.c, runs in 11 cursor blinks.

/* BEGIN new.c */

#include <stdio.h>
#include <limits.h>

long unsigned fib(int n);
void lutoa(long unsigned n, char *s);

int main(void)
{
FILE *fp;
long unsigned loop = 10000000;
char lutoa_buff[(sizeof(long) * CHAR_BIT ) / 3 + 1];

if ((fp = fopen("log.txt" , "w")) != NULL) {
do {
lutoa(fib(10), lutoa_buff);
fputs(lutoa_buf f, fp);
putc('\n', fp);
} while (--loop != 0);
fclose (fp);
}
return 0;
}

long unsigned fib(int n)
{
long unsigned r = 1;

while (n 1) {
r *= n--;
}
return r;
}

void lutoa(long unsigned n, char *s)
{
long unsigned tenth;
char *p, swap;

p = s;
tenth = n;
do {
tenth /= 10;
*p++ = (char)(n - 10 * tenth + '0');
n = tenth;
} while (tenth != 0);
*p-- = '\0';
while (p s) {
swap = *s;
*s++ = *p;
*p-- = swap;
}
}

/* END new.c */

--
pete

[c]

On Dec 13, 3:07 am, pete <pfil...@mindsp ring.comwrote:

c wrote:

Hi every one,

Me and my Cousin were talking about C and C#, I love C and he loves
C#..and were talking C is ...blah blah...C# is Blah Blah ...etc

and then we decided to write a program that will calculate the
factorial of 10, 10 millions time and print the reusult in a file with
the name log.txt..

I wrote something like this

#include <stdio.h>
unsigned int fib (int n);

int main()
{
FILE *fp;
unsigned int loop =1 ;
if ( (fp = fopen( "log.txt", "a" )) != NULL )
for (loop; loop <= 10000000 ; loop++)
{

fprintf(fp,"%u\ n",fib(10));
}
fclose (fp);
return 0;
}

unsigned int fib (int n)
{ if (n != 1 )
return n * fib(n-1);
else
return 1;
}

and he did the something in C#

and then we all have the same laptop..DELL Inspiron 6000.

I ran my program, I took 18 seconds to get done..his program took 7
seconds..Wow

and then I asked him to run my program in his laptop..it's all the
same ..but I wanted to...I ran it...gave me the same time..

How come ..?!

Next day, I tried some Optimization

and developed the loop and wrote something like this

for (loop; loop <= 1000000 ; loop++)
{
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
fprintf(fp,"%u\ n %u\n %u\n %u\n %u\n
",fib(10),fib(1 0),fib(10),fib( 10),fib(10));
}

But his program still faster than mine..

then, I tried the program under Slackware 12....it took 3.8 Seconds to
get done..Wow, I won the Challenge..

anyway, he want me to beat him under windows XP...Please guys help me
out..

My first guess is that fprintf is your slowest dog.
The second most obvious improvement would be to
remove recursion from your fib function.

Your program runs in 19 cursor blinks on my machine.
My program, new.c, runs in 11 cursor blinks.

/* BEGIN new.c */

#include <stdio.h>
#include <limits.h>

long unsigned fib(int n);
void lutoa(long unsigned n, char *s);

int main(void)
{
FILE *fp;
long unsigned loop = 10000000;
char lutoa_buff[(sizeof(long) * CHAR_BIT ) / 3 + 1];

if ((fp = fopen("log.txt" , "w")) != NULL) {
do {
lutoa(fib(10), lutoa_buff);
fputs(lutoa_buf f, fp);
putc('\n', fp);
} while (--loop != 0);
fclose (fp);
}
return 0;

}

long unsigned fib(int n)
{
long unsigned r = 1;

while (n 1) {
r *= n--;
}
return r;

}

void lutoa(long unsigned n, char *s)
{
long unsigned tenth;
char *p, swap;

p = s;
tenth = n;
do {
tenth /= 10;
*p++ = (char)(n - 10 * tenth + '0');
n = tenth;
} while (tenth != 0);
*p-- = '\0';
while (p s) {
swap = *s;
*s++ = *p;
*p-- = swap;
}

}

/* END new.c */

--
pete

thanks pete...
But I gotta use recursion..It's not fair..My friend uses recursion in
his program, the program that he wrote in C#..So I have to :-)
otherwise, I am cheating.

Thank you very much.