C语言求1/n的和，

#include <stdio.h>

main ()

{

      

       doubleq,m=2,n,sum=0;

   scanf("%lf",&n);

       while(n<=20)

       {

              q=m/n;

              m=m+n;

              n++;

              sum=sum+q;

              printf("%lf\n",sum);

             

       }

       printf("最后sum=%lf",sum);