语句练习题1

 1         double fm=0;
 2         double fz=0;
 3         double sum=0;
 4         for(int i=1;i<=20;i++){
 5             if(i==1){
 6                 fz=2;
 7                 fm=1;
 8                 sum=sum+fz/fm;
 9             }else{
10                 double t=fz;
11                 fz=fz+fm;
12                 fm=t;
13                 sum=sum+fz/fm;
14             }
15         }
16         System.out.println("分数序列前20项的和="+sum);