how many fibs java_hdu 1316 How Many Fibs?【JAVA大数】

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)

Total Submission(s): 2814    Accepted Submission(s): 1112

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

Recommend

Eddy

又钻了 JAVA 的空子，一下就 AC 了，

但是奇怪的是，为什么我把内存减少一半，空间没有节省多少，时间反而多了一些

8276754

2013-05-10 16:30:33

Accepted

171MS

3704K

Java

8276732

2013-05-10 16:28:32

Accepted

140MS

3752K

Java

import java.util.*;

import java.math.*;

import java.io.*;

public class Main {

public static void main(String args[]) {

BigInteger []f = new BigInteger[500];

f[1] = new BigInteger("1");

f[2] = new BigInteger("2");

for(int i = 3; i < 500; i++) {

f[i] = f[i-1].add(f[i-2]);

}

/*

String s = f[499].toString(); //算出有 105 位

int len = s.length();

System.out.println(len);

*/

Scanner cin = new Scanner(new BufferedInputStream(System.in));

BigInteger a,b;

BigInteger c = BigInteger.valueOf(0);

while(cin.hasNextBigInteger()) {

a = cin.nextBigInteger();

b = cin.nextBigInteger();

if(a.compareTo(BigInteger.valueOf(0)) == 0 && b.compareTo(c) == 0) {

break;

}

int ans = 0;

for(int i = 1; i < 500; i++) {

if(f[i].compareTo(b) == 1) {

break;

}

if(f[i].compareTo(a) >= 0 && f[i].compareTo(b) <= 0) {

ans++;

}

}

System.out.println(ans);

}

}

}