杭电ACM2011-- 多项式求和

题目地址 ：多项式求和

/*
#include<stdio.h>
int main()
{
    int n,b;
    double a[110],x;
    double z;
    int i,j;
    int f;
    for (i=1;i<101;i++)
        a[i]=(double)1/(double)i;

    scanf("%d",&n);
    while(n--)
    {
        scanf("%d",&b);
        z = 0;
        f = 1;
        //printf("%d\n",b);
        for (i=1;i<=b;i++)
        {
            x = f*a[i];
            z = z+x;
            f = -1*f;
        }
        printf("%.2lf\n",z);
    }

    return 0;
}

*/

/*
#include<stdio.h>
int main()
{
    float a[110];
    int i,f,n,c;
    f = 1;
    a[0]=0;
    for (i=1;i<101;i++)
    {
        a[i]=a[i-1]+f*1.0/(float)i;
        f=-f;
    }
    scanf("%d",&n);

    for (i=0;i<n;i++)
    {
        scanf("%d",&c);
        //printf("%d\n",b);
        printf("%.2f\n",a[c]);
    }
    return 0;
}
*/

#include<stdio.h>
int main()
{
    int a[110];
    double x,s;
    int i,n,m,j,f;
    scanf("%d",&n);
    for (i=1;i<=n;i++)
        scanf("%d",&a[i]);
    for (i=1;i<=n;i++)
    {
        f = 1;
        s = 0;
        for (j=1;j<=a[i];j++)
        {
            s=s+1.0/j*f;
            f=-f;
        }
        printf("%.2f\n",s);
    }
    return 0;
}