Getting Floating point: overflow error in factorial code

[y8ycgl]

i have a program that i made in my class in Turbo C++ on windows 95or98 i belive. it is made to solve for factorials. th problem is that :
A) it puts it in exponents
B) theres too many numbers to count so i need a way to put commas every 3 digits and i dont know how to do that.
C) any factorials over 1754 give the computer an error that says:
Floating point: overflow
here is my program:

#include<iostream.h>
#include<iomanip.h>
#include<conio.h>
void main ()
 {
  long double bfn=0;
  long int m=0;
  char pause;
  cout<<setiosflags(ios::fixed|ios::showpoint|ios::right)<<setprecision(0);
  cout<<"type what you want a factorial of"<<endl;
  cin>>bfn;
  m=bfn-1;
   while (m>0)
    {
      bfn=bfn*m;
      m=m-1;
      cout<<bfn<<endl;
    }
  cout<<bfn<<endl<<endl;
 }
 

how can i fix these problems?

[NeoPa]

I'm sure digits #8,384 through #9,131 are correct Jos, but are you sure about digit #5,648 (000535258)?

PS. I think he may just get it after your post ;D

[y8ycgl]

@_@ hmmmm
so how would i begin writing a program with a vector/array? i dont quite know the code just yet. but if you do tell me a line of code i would also like to understand it, so please tell me what it means.......>.>

[sicarie]

I would suggest researching vectors and arrays and deciding which one you want, as the datatypes behave differently. Pick the one you feel would be best served in your application, then look it up through Google.

[y8ycgl]

and NeoPa ..... HOW DID YOU FIND THAT? did you compare the entire number?........ ....

[NeoPa]

No. I was bluffing mainly. I'm sure Jos's answer is 100% accurate.
I have a text editor that shows what position it's at so counting the length of the number wasn't hard. With so many multiples of ten in the calculation it's obvious that there will be many zeroes at the end of the number.

[y8ycgl]

well that solves the problem.... but i thought i would have fun making this program. i havent much idea as to the code part of what im doing.

[NeoPa]

If you ever learned long-multiplication at school, then that's the sort of process you need to be thinking of duplicating. String variables would be required to hold your working variables.