经典递归求斐波那契数列

public class Test3 {//4
public static void main(String[] args){
double n=30;
f(n);
System.out.println(f(n));
}
public  static  double f(double n) {
if(n==1){
return 1;
}
if(n==2){
return f(n-1)+1;
}
return f(n-1)+f(n-2);
}
}