这段代码为啥无法输出正确值

Question

int i=1,a=1;
    double s=0;
    do
    {
            a=a*i;
            s=s+1/a;
            i++;
    }while(a<100000);
    printf("%lf\n",s);

Answer 1

把s=s+1/a;改成s=s+1.0/a;