How Many Fibs_hdu_1316(大数).java

How Many Fibs?

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 3098    Accepted Submission(s): 1232

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 1001234567890 98765432100 0

 

Sample Output

54

 

import java.math.BigInteger;import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner input=new Scanner(System.in);BigInteger f[]=new BigInteger[505];f[0]=BigInteger.valueOf(1);f[1]=BigInteger.valueOf(2);for(int i=2;i<502;i++){f[i]=f[i-1].add(f[i-2]);}while(true){BigInteger a=input.nextBigInteger();BigInteger b=input.nextBigInteger();if(a.equals(BigInteger.ZERO)&&b.equals(BigInteger.ZERO))break;int sum=0;for(int i=0;i<502&&b.compareTo(f[i])>=0;i++){if(f[i].compareTo(a)>=0)sum++;}System.out.println(sum);}}}