C语言 计算数列2/1,3/2,5/3,8/5,13/8,21/13……前n项和

Posted 2021-05-14 Aiden (winner)

#include<stdio.h>
int main(){
    double x=2,y=1,sum=0,t; 
    int i,n;
	printf("请输入求和项数：");
	scanf("%d",&n);
    for(i=1;i<=n;i++){
        sum+=x/y;
        t=x;
        x=y+x;
        y=t;
    }
	printf("2/1,3/2,5/3,8/5,13/8,21/13……前%d项和为：%f \\n",n,sum);
}