#include <stdio.h>
int main (void)
{
   int n,i,a,b,c=1;
   float sum=0;                    
   fprintf(stdout,"请输入值\n");
   fscanf(stdin,"%d",&n);
    for(i=1;i<=n;i++)
    {
       a=1/i;
       b=c*a;
       c=b;
       sum=sum+(float)b;
    }
    fprintf(stdout,"%f",sum);
    return 0;
}哪里错了

谢谢了    问题解决了