4-3 求序列和

//求序列和#include<stdio.h>int main(int argc,char const *argv[]){int n,i;double sum=0;scanf("%d",&n);double x1=1,x2=1,t;double item;for(i=1;i<=n;i++){t=x1+x2;x2=x1;x1=t;item=x1/x2;sum=sum+item;//printf("x1=%.2f,x2=%.2f,item=%.2f,sum=%.2f\n",x1,x2,item,sum);}printf("sum=%.2f\n",sum);return 0;}