C语言斐波那契数列

解题思路:

注意事项:

参考代码:

#include <stdio.h>

#include <math.h>

int main()

{

    int N;

    scanf("%d",&N);

float  s=0,sum=0,fn1=1.0,fn2=2.0,fn3=0;

for(int i=0;i<N;i++){

sum+=fn2/fn1;

fn3=fn1+fn2;

fn1=fn2;

fn2=fn3;

}

    printf("%.2f",sum);

    return 0;

}