hdu_2011多项式求和

#include<cstdio>int main(){    int c,t,f;    scanf("%d",&c);    double sum = 0;    for(int j = 0;j < c;++j)    {        sum = 0;        f= 1;        scanf("%d",&t);        for(int i = 1;i<=t;++i)        {            sum += 1/double((i*f));            f *= -1;        }        printf("%.2f\n",sum);    }}