hdu1316 java解高精度斐波数

How Many Fibs?

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 3334    Accepted Submission(s): 1340

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

 

import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Scanner;

public class Main {
	public static void main(String []args)throws Exception{
		Scanner cin = new Scanner(System.in);
		while(cin.hasNext()){
		String a=cin.next();
		String b=cin.next();
		if(a.equals("0")&&b.equals("0"))
			break;
		BigInteger c = new BigInteger(a);
		BigInteger d = new BigInteger(b);
		int sum=fibo(c,d);
		System.out.println(sum);
		}
		cin.close();
	}
	public static int fibo(BigInteger a,BigInteger b){
		int sum =0;
		BigInteger f = new BigInteger("1");
		BigInteger s = new BigInteger("2");
		while(true){
			
			if(f.compareTo(b)>0)
				break;
			if(f.compareTo(a)>=0)
				sum++;
			BigInteger tem = f;
			f=s;
			s=s.add(tem);
		}
		return sum;
	}
}