HDU 1056

递推

#include <iostream>
using namespace std;
double f[10000];
double c;
int main()
{    
    f[0]=0;
    for(int i=1;i<=10000;i++) f[i]=1.0/(i+1)+f[i-1];
    while(cin>>c,c!=0)
    {
        int m=1;
         while(f[m]<c) m++;
         cout<<m<<" card(s)
";
    }
}