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【JAVA大数训练】How Many Fibs?

How Many Fibs?

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 3628    Accepted Submission(s): 1457


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.math.BigInteger;
import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner input=new Scanner(System.in);
		BigInteger [] p=new BigInteger[10010];
        p[1]=BigInteger.valueOf(1);p[2]=BigInteger.valueOf(2);
		for (int i = 3; i<=10000; i++) {
			p[i]=p[i-1].add(p[i-2]);
		}
		while(input.hasNext())
		{
			BigInteger n=input.nextBigInteger();
			BigInteger m=input.nextBigInteger();
			int sum=0;
			if(n.compareTo(BigInteger.ZERO)==0&&m.compareTo(BigInteger.ZERO)==0)
			break;
			for (int i = 1; i <=10000; i++) {
				if(p[i].compareTo(n)>=0&&p[i].compareTo(m)<=0)
					sum++;
			}
		    System.out.println(sum);
		}
	}
}





 


总结


BigIngter a与BigIngter b比大小


如果a比b大


a.compareTo(b)>0


如果a比b小


a.compareTo(b)<0


如果a等于b


a.compareTo(b)==0


 


最后更新：2017-04-03 12:56:11
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