学步园

http://162.105.81.212/JudgeOnline/problem?id=2413

高精度题目, 用Java水过.

有一个常识值得说下, Fib数列的第500项约为10^105

所以打标Fib的前500项即可.

import java.io.BufferedInputStream;<br /> import java.math.BigInteger;<br /> import java.util.Scanner;<br /> public class Main {<br /> public static void main(String[] args) {<br /> Scanner in = new Scanner(new BufferedInputStream(System.in));<br /> BigInteger big[] = new BigInteger[501];<br /> big[1] = BigInteger.valueOf(1);<br /> big[2] = BigInteger.valueOf(2);<br /> for(int i=3; i<=500; i++)<br /> big[i] = big[i-1].add(big[i-2]);<br /> int i, ret;<br /> BigInteger a, b;<br /> while(true) {<br /> a = in.nextBigInteger();<br /> b = in.nextBigInteger();<br /> if(a.compareTo(b) == 0 && a.compareTo(BigInteger.valueOf(0)) == 0)<br /> break;<br /> i = 1;<br /> ret = 0;<br /> while(big[i].compareTo(a) < 0)<br /> i++;<br /> while(big[i].compareTo(b) <= 0) {<br /> ret++;<br /> i++;<br /> }<br /> System.out.println(ret);<br /> }<br /> }<br /> }<br />