杭电1316（How Many Fibs?）

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Problem Description

Recall the definition of the Fibonacci numbers:

f1 := 1

f2 := 2

fn := fn-1 + fn-2 (n >= 3)

Given two numbers a and b, calculate how many Fibonacci numbers are in the range [a, b].

Input

The input contains several test cases. Each test case consists of two non-negative integer numbers a and b. Input is terminated by a = b = 0. Otherwise, a <= b <= 10^100. The numbers a and b are given with no superfluous leading zeros.

Output

For each test case output on a single line the number of Fibonacci numbers fi with a <= fi <= b.

Sample Input

10 100
1234567890 9876543210
0 0

Sample Output

5
4

代码实现

import java.math.BigInteger;
import java.util.Scanner;
class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        BigInteger[] fib=new BigInteger[1005];
        fib[1]=BigInteger.valueOf(1);
        fib[2]=BigInteger.valueOf(2);
        for(int i=3;i<1005;i++){
        	fib[i]=fib[i-1].add(fib[i-2]);
        }
        int numb;
        while(sc.hasNextBigInteger()){
	        BigInteger a=sc.nextBigInteger();
            BigInteger b=sc.nextBigInteger();
            if(a.equals(BigInteger.valueOf(0))&&b.equals(BigInteger.valueOf(0))){
            	break;
            }
        	numb=0;
            for(int i=1;i<1005;i++){
            	if(fib[i].compareTo(a)>=0&&fib[i].compareTo(b)<=0){
            		numb++;
            	}
            	if(fib[i].compareTo(b)>0){
            		break;
            	}
            }
            System.out.println(numb);
        }
    }
}