Shell Necklace
Time Limit: 16000/8000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 1587 Accepted Submission(s): 721
Problem Description
Perhaps the sea‘s definition of a shell is the pearl. However, in my view, a shell necklace with n beautiful shells contains the most sincere feeling for my best lover Arrietty, but even that is not enough.
Suppose the shell necklace is a sequence of shells (not a chain end to end). Considering i continuous shells in the shell necklace, I know that there exist different schemes to decorate the i shells together with one declaration of love.
I want to decorate all the shells with some declarations of love and decorate each shell just one time. As a problem, I want to know the total number of schemes.
Input
Output
For each test case, print one line containing the total number of schemes module
313(Three hundred and thirteen implies the march 13th, a special and purposeful day).
Sample Input
Sample Output
14 54
Hint
For the first test case in Sample Input, the Figure 1 provides all schemes about it. The total number of schemes is 1 + 3 + 3 + 7 = 14.
Author
HIT
Source
2016 Multi-University Training Contest 1
递推式很显然
然而这个东西虽然是卷积 但显然不能直接FFT
所以呢 分治FFT/NTT !
具体来讲就是
每次处理区间 [l,r]
先处理 [l,mid]
对于 [l,mid] 已求出真值 处理其对 [mid+1,r] 取值的影响
之后再处理 [mid+1,r]
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