HOJ 1637 HangOver

http://acm.hit.edu.cn/hoj/problem/view?id=1637

#include <stdio.h>
#include <math.h>

int fun(double c);

int main()
{
    double c;
    
    while (scanf("%lf", &c) && c)
    {
        printf("%d card(s)\n", fun(c));
    }
    
    return 0;
}

int fun(double c)
{
    int i;
    double s;

    s = 0;
    for (i = 2;;i++)
    {
        s += pow(i, -1.0);
        if(s >= c)
        break;
    }
    return i - 1;
}