hdu_2011 多项式求和

import java.text.DecimalFormat;
import java.util.Scanner;

/**
 * Created by feyman1120 on 2017/11/23.
 */

public class Main {
    public static void main(String [] args){

        Scanner scan = new Scanner(System.in);
        int m = scan.nextInt();
        for (int i = 0; i < m; ++i){
            int n = scan.nextInt();
            double sum = 0;
            double pos = 1.0;
            for (int j = 1; j <= n; ++j){
                sum += 1.0 / j * pos;
                pos *= -1.0; /*正负关系交替变化*/
            }
            DecimalFormat df = new DecimalFormat("#0.00");
            System.out.println(df.format(sum));
        }
    }
}