杭电ACM2011-- 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;
}