We have to start from 1 to the limit specfied say n.Start from 1*2*3...*n.
In c, i am writing it as a function.
main()
{
int n;
scanf("%d",&n);
printf("%ld",fact(n));
}
long int fact(int n)
{
long int facto=1;
int i;
for(i=1;i<=n;i++)
{
facto=facto*i;
}
return facto;
}