HDU 1316-How Many Fibs?（大数类）

How Many Fibs?

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 4295    Accepted Submission(s): 1689

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 1001234567890 98765432100 0

 

Sample Output

54
给出一个范围[l,r],求此范围内的斐波那契数的个数。打表即可。
import java.io.*;import java.util.*;import java.math.*;public class Main {       public static void main(String[] args){       Scanner in=new Scanner(System.in);       BigInteger a,b,cnt;BigInteger[] f=new BigInteger[10010];       f[1]=BigInteger.valueOf(1);f[2]=BigInteger.valueOf(2);       for(int i=3;i<10005;i++)       f[i]=f[i-1].add(f[i-2]);       while(in.hasNext()){       cnt=BigInteger.ZERO;               a=in.nextBigInteger();b=in.nextBigInteger();               if(a.equals(BigInteger.valueOf(0))&&b.equals(BigInteger.valueOf(0)))break;           for(int i=1;i<10000;i++)          if((f[i].compareTo(a)==0||f[i].compareTo(a)==1)&&(f[i].compareTo(b)==0||f[i].compareTo(b)==-1))          cnt=cnt.add(BigInteger.valueOf(1));           System.out.println(cnt);       }       }}