View Code of Problem 48

#include<stdio.h>
int main(){
	int i,n;
	scanf("%d",&n);
	double sum = 0.0;
	int fz1 = 2, fz2 = 3, fm1 = 1, fm2 = 2, fz3, fm3;
	for(i = 1;i <= n; i ++){
		if(i == 1){
			sum = sum + (double)fz1 / fm1;
		}else if(i == 2){
			sum = sum + (double)fz2 / fm2;
		}else{
			fz3 = fz1 + fz2;
			fm3 = fm1 + fm2;
			sum = sum + (double)fz3 / fm3;
			fz1 = fz2;
			fz2 = fz3;
			fm1 = fm2;
			fm2 = fm3;
		}
	}
	printf("%.6lf\n",sum);
	return 0;
}