How Many Fibs? 字符串转换处理

 1 import java.util.*;
 2 import java.io.*;
 3 import java.lang.*;
 4 import java.math.*;
 5 import java.text.*;
 6 class Main
 7 {
 8     public static void main(String args[])
 9     {
10         Scanner cin=new Scanner(System.in);
11         int i,j=0,k=0,flags;
12         BigInteger a,b,c[]=new BigInteger[501];
13         c[0]=BigInteger.valueOf(1);
14         c[1]=BigInteger.valueOf(2);
15         String s1,s2;
16         for(i=2;i<500;i++)
17         {
18             c[i]=c[i-1].add(c[i-2]);
19         }
20         while(cin.hasNext())
21         {
22             flags=0;
23             s1=cin.next();
24             s2=cin.next();
25             a=new BigInteger(s1);
26             b=new BigInteger(s2);
27             if(b.compareTo(BigInteger.valueOf(0))==0)break;
28             for(i=0;i<500;i++)
29             {
30                 if(flags==0)
31                 {
32                     if(c[i].compareTo(a)>=0)
33                     {
34                         j=i;
35                         flags=1;
36                     }
37                 }
38                 if(c[i].compareTo(b)==1)
39                 {
40                     k=i;
41                     break;
42                 }
43             }
44             System.out.println(k-j);
45         }
46     }
47 }