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);
	}
}