Queuing
Time Limit: 10000/5000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 4638 Accepted Submission(s): 2045
Problem Description
Queues
and Priority Queues are data structures which are known to most
computer scientists. The Queue occurs often in our daily life. There are
many people lined up at the lunch time. 
Now we define that ‘f’ is short for female and ‘m’ is short for male. If the queue’s length is L, then there are 2L
numbers of queues. For example, if L = 2, then they are ff, mm, fm, mf .
If there exists a subqueue as fmf or fff, we call it O-queue else it is
a E-queue.
Your task is to calculate the number of E-queues mod M with length L by writing a program.
Input
Input a length L (0 <= L <= 10 6) and M.
Output
Output K mod M(1 <= M <= 30) where K is the number of E-queues with length L.
Sample Input
3 8
4 7
4 8
Sample Output
6
2
1
Author
WhereIsHeroFrom
Source
HDU 1st “Vegetable-Birds Cup” Programming Open Contest
Recommend
lcy
对于长度为n的队列q(n)，做以下讨论。
图中 ，".....m"表示以字符‘m‘结尾的queue，其它类似。E_q表示E_queue。
可得q(n)=q(n-1)+q(n-3)+q(n-4)
转换为矩阵，运用矩阵快速幂运算进行求解。
即，
n>=4,
