View Code of Problem 71

#include<stdio.h>
int main(){
    int up=2,down=1;
    int n;
    int m;
    int i;
    double sum=0.0;
    scanf("%d",&n);
    for(i=0;i<n;i++){
        sum=sum+up*1.0/down*1.0;
        m=up;
        up=up+down;
        down=m;
    }
    printf("%.2f",sum);
    return 0;
}