HDOJ 1316 How Many Fibs?

JAVA大数....

How Many Fibs?

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

Total Submission(s): 3906    Accepted Submission(s): 1545


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

 

Source

University of Ulm Local Contest 2000

 

import java.util.*;
import java.math.*;
import java.io.*;

public class Main
{
public static void main(String[] args)
{
Scanner cin=new Scanner(System.in);

final BigInteger maxlimit=BigInteger.TEN.pow(100);
BigInteger[] fib=new BigInteger[500];

fib[0]=BigInteger.ONE;
fib[1]=BigInteger.valueOf(2);

for(int i=2;i<500;i++)
{
fib[i]=fib[i-1].add(fib[i-2]);
}

while(cin.hasNextBigInteger())
{
BigInteger a=cin.nextBigInteger();
BigInteger b=cin.nextBigInteger();
if(a.compareTo(BigInteger.ZERO)==0&&b.compareTo(BigInteger.ZERO)==0)
break;
int ans=0;
for(int i=0;i<500;i++)
{
if(fib[i].compareTo(a)>=0&&fib[i].compareTo(b)<=0)
ans++;
}
System.out.println(ans);
}
}
}