Factorial..

[arunraj2002in]

Hi All,

I have a doubt
[code=c]
void myfun(int x)
{
if(x>0)
myfun(--x);

printf("%d",x);
}

int main()
{
myfun(5)
return 0;
}
[/code]
Here the output is : 0,0,1,2,3,4. Can you tell why?

[tnga]

Hi All,

I have a doubt
[code=c]
void myfun(int x)
{
if(x>0)
myfun(--x);

printf("%d",x);
}

int main()
{
myfun(5)
return 0;
}
[/code]
Here the output is : 0,0,1,2,3,4. Can you tell why?

That's a recursion, dude...
it goes recursioning until x=0
then it prints and come back
since you have myfun(--x), x is decremented before the function is called... That's why you have two zerous and no five...

Best regards,

TNGA

[weaknessforcats]

void myfun(int x)
{
if(x>0)
myfun(--x);

printf("%d",x);
}

When x is 1, you call myfun(--x). That call prints 0. Then you return to this call and the x is still 0. So you print 0 again.

Maybe you should:
[code=cpp]
void myfun(int x)
{
if(x>0)
myfun(x - 1);

printf("%d",x);
}
[/code]

[arunraj2002in]

When x is 1, you call myfun(--x). That call prints 0. Then you return to this call and the x is still 0. So you print 0 again.

Maybe you should:
[code=cpp]
void myfun(int x)
{
if(x>0)
myfun(x - 1);

printf("%d",x);
}
[/code]

Now if we modify the program:
void myfun(int x)
{
if(x>0)
myfun(x--);

printf("%d",x);
}

int main()
{
myfun(5);
return 0;
}

This leads to Segmentation fault.. why?

[JosAH]

Now if we modify the program:
void myfun(int x)
{
if(x>0)
myfun(x--);

printf("%d",x);
}

int main()
{
myfun(5);
return 0;
}

This leads to Segmentation fault.. why?

Note that the value of the expression "x--" happens to be the same as "x".
In other words your resursion never stops and overflows the stack, hence the
segmentation violation.

kind regards,

Jos