hdu1316 How Many Fibs

How Many Fibs?

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 7257    Accepted Submission(s): 2842

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

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

public class BigNumber{
	
	public static void main(String[] args){
		
		Scanner input = new Scanner(System.in);
		int i,cnt;
		BigInteger []arr = new BigInteger[480];
		BigInteger a,b;
		
		
		arr[0] = new BigInteger("1");
		arr[1] = new BigInteger("2");
		for(i=2; i<480; i++)
			arr[i]=arr[i-1].add(arr[i-2]);
		
		
		while(true){
			a=input.nextBigInteger();
			b=input.nextBigInteger();
			if(a.equals(BigInteger.ZERO)&&b.equals(BigInteger.ZERO))
				break;
			i=0;
			cnt=0;
			while(arr[i].compareTo(b)<=0){
				if(arr[i].compareTo(a)>=0)
					cnt++;
				i++;
			}
			System.out.println(cnt);

		}
	}
}