斐波那契反向求index

package Fibonacci;

import java.util.Scanner;

import java.util.function.ObjLongConsumer;

public class Demo {

public static void main(String[] args) {

// TODO Auto-generated method stub

System.out.println("输入一个数：");

Scanner scanner = new Scanner(System.in) ;

long n = scanner.nextLong();

long num = scanner.nextLong();

/* System.out.println("数所对应的Fibonacci的值：" + fib(n));

System.out.println("非递归-index所对应的Fibonacci的值：" + fibIndex(n));

*/ 

System.out.println("反向求index:");

fibReturn(n, num);

}

public static void fibReturn(long n ,long num) {

long f0 = 0;

long f1=1;

long f2= 1 ;

if(num == 0 )

System.out.println("0");

    if(num == 1 || num ==2)

    System.out.println("1");

for(int i= 3 ; i <=n ; i++) {

    f0 = f1 ;

f1 = f2 ;

f2 = f0 + f1 ;

if(f2 ==num) {

System.out.println("此数所对应的索引值" + i);

    }

}

  }

}