HDU 1316-How Many Fibs?（大数类）

How Many Fibs?

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)

Total Submission(s): 4295 Accepted Submission(s): 1689



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给出一个范围[l,r],求此范围内的斐波那契数的个数。打表即可。
import java.io.*;
import java.util.*;
import java.math.*;
public class Main {
       public static void main(String[] args){
    	   Scanner in=new Scanner(System.in);
    	   BigInteger a,b,cnt;BigInteger[] f=new BigInteger[10010];
    	   f[1]=BigInteger.valueOf(1);f[2]=BigInteger.valueOf(2);
    	   for(int i=3;i<10005;i++)
    		   f[i]=f[i-1].add(f[i-2]);
    	   while(in.hasNext()){
    		   cnt=BigInteger.ZERO;
               a=in.nextBigInteger();b=in.nextBigInteger();
               if(a.equals(BigInteger.valueOf(0))&&b.equals(BigInteger.valueOf(0)))break;
    	       for(int i=1;i<10000;i++)
    		      if((f[i].compareTo(a)==0||f[i].compareTo(a)==1)&&(f[i].compareTo(b)==0||f[i].compareTo(b)==-1))
    		    	  cnt=cnt.add(BigInteger.valueOf(1));
    	       System.out.println(cnt);
    	   }
       }
}