UVA 10183 斐波那契数列

Problem B: How many Fibs?

Recall the definition of the Fibonacci numbers:

f₁:= 1
f₂:= 2
f_n:=f_n-1+f_n-2 (n>=3)

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

Input Specification

The input contains several test cases. Each test case consists of two non-negative integer numbersaandb. Input is terminated bya=b=0. Otherwise,a<=b<=10¹⁰⁰. The numbersaandbare given with no superfluous leading zeros.

Output Specification

For each test case output on a single line the number of Fibonacci numbersf_iwitha<=f_i<=b.

Sample Input

10 100
1234567890 9876543210
0 0

Sample Output

5
4

直接利用java大数可以水过

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

public class Main {
	public static void main(String args[])
	{
		Scanner cin=new Scanner(System.in);
		BigInteger f[]=new BigInteger[1000];
		BigInteger a,b;
		int i,ans;
		f[1]=BigInteger.ONE;
		f[2]=BigInteger.valueOf(2);
		for(i=3;i<1000;i++)
			f[i]=f[i-1].add(f[i-2]);
		while(true)
		{
			a=cin.nextBigInteger();
			b=cin.nextBigInteger();
			if(a.compareTo(b)>0)
			{
				System.out.println(0);
				continue;
			}
			if(a.compareTo(BigInteger.ZERO)==0&&b.compareTo(BigInteger.ZERO)==0)
				break;
			ans=0;
			for(i=1;i<1000;i++)
			{
				if(f[i].compareTo(a)>=0&&f[i].compareTo(b)<=0)
					ans=ans+1;
			}
			System.out.println(ans);
		}
	}
}