这道题怎么做，哪位帮看下

供参考：

#include<stdio.h>
int main()
{
    int n, i, k = 1, m = 2, t;
    double sum = 0;
    scanf("%d", &n);
    if (n > 30) return 1;
    for (i = 1; i <= n; i++)
    {
        sum += 1.0 * m / k;
        t = m;
        m = m + k;
        k = t;
    }
    printf("%d\n", (int)sum);
    return 0;
}

#include <stdio.h>
#define N 30
int main()
{
int i,n;
int a[N],b[N];
float sum=0;
a[0]=1;a[1]=2;
b[0]=2;b[1]=3;
scanf("%d",&n);
if(n==1) sum=2;
else if(n==2) sum = 2/1+3/2.0;
else{
sum = 2/1+3/2.0;
for(i=2;i<n;i++)
{
a[i] = a[i-1]+a[i-2];
b[i]=b[i-1]+b[i-2];
sum += 1.0* b[i]/a[i];
}
}
printf("%d",(int)sum);
return 0;
}