java笔试题之递归求1+1/2-1/3+1/4-1/5.....的前n项和

一道很简单的笔试题，还是思考了很久，记录一下。

public class Main {
    public static void main(String[] args) {
        Main main = new Main();
        System.out.println(main.count(2));
    }

    public double count(int n){
        if (n==0) return 0;
        if (n==1) return 1;
        if (n%2==0){
            return  (double) 1/n + count(n-1);
        }else
            return (double)-1/n + count(n-1);
    }
}