> #include<iostream>
> using namespace std;
> 
> int hangover( double x)
> {
> 	int n=1;
> 	double cardlength,a,b;
> 	cardlength = 1.0 / (n + 1);
> 	for (cardlength;cardlength<x;cardlength += 1.0 / (n + 1))
> 	{
> 		n++;
> 	}
> 	a = cardlength-1.0/(n+1);
> 	b = cardlength;
> 	if ((x - a) > (b - x))
> 	{
> 		return n;
> 	}
> 	else
> 		return n-1;
> }
> 
> int main()
> {
> 	double x;
> 	while (cin >> x&&x!=0.00)
> 	{
> 		int	 n=hangover(x);
> 		cout << n << " card(s)" << endl;
> 	}
> 	return 0;
> }

不需要 if ((x - a) > (b - x)) 的判断