F.A.Q
Hand In Hand
Online Acmers
Problem Archive
Realtime Judge Status
Authors Ranklist
 
     C/C++/Java Exams     
ACM Steps
Go to Job
Contest LiveCast
ICPC@China
Best Coder beta
VIP | STD Contests
    DIY | Web-DIY beta
Author ID 
Password 
 Register new ID

斐波纳契的秘密

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others)
Total Submission(s): 1    Accepted Submission(s): 1


Problem Description
某某学者发现,将斐波那契数列mod $M$会呈现周期性。比如下面以$M = 11$为例:

n | 1 2 3 4 5 6 7 8 9 10
F(n) | 1 1 2 3 5 8 13 21 33 55
F(n) mod 11 | 1 1 2 3 5 8 2 10 1 0

我们可以知道当$n = 11$时和$n = 1$时相等且以后会周期性重复之前的数字,即当$M = 11$时,周期长度为$10$.我们假设$F(M)$为周期的长度,则$F(11) = 10$。另外我们发下一些有趣的性质:
如果$M > 2,F(M)$为偶数。
$F(M) \leq M^2 - 1$
$F(2n) = 3 * 2^{n - 1}$
$F(5n) = 4 * 5n$
$F(2 * 5n) = 6n$
$F(10n) = 15 * 10^{n - 1} (n > 2)$
现在我们想知道给定$M$,求$F(M)$是多少?
 

Input
第一行 $T$,表示 $T$个测试样例,$(1 \leq T \leq 1000)$,接下来$T$行,每行两个整数 $N, M$
$N$表示第几个样例,$M(2 \leq M \leq 1000000)$如题目描述。
 

Output
输出当前样例编号(第几个样例)和求得的$F(M)$.
 

Sample Input
4 1 4 2 5 3 11 4 123456
 

Sample Output
1 6 2 20 3 10 4 15456
 

Source
 

Statistic | Submit | Discuss | Note
Hangzhou Dianzi University Online Judge 3.0
Copyright © 2005-2025 HDU ACM Team. All Rights Reserved.
Designer & Developer : Wang Rongtao LinLe GaoJie GanLu
Total 0.000000(s) query 1, Server time : 2025-03-29 19:22:34, Gzip enabled