题库练习 Xor-sequences
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A10552 | Xor-sequences

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题目描述

You are given $n$ integers $a_{1},a_{2},...,a_{n}$ .

A sequence of integers $x_{1},x_{2},...,x_{k}$ is called a "xor-sequence" if for every $1<=i<=k-1$ the number of ones in the binary representation of the number $x_{i}$ ![](/uploads/acgo/image/656bceeccf10e28d_6cfcd6386813.jpeg) $x_{i+1}$ 's is a multiple of $3$ and ![](/uploads/luogu/CF691E/187abd20483c4318d7cd71518f323b9990bcdd61_aa6b2c5dc1cb.png) for all $1<=i<=k$ . The symbol ![](/uploads/acgo/image/656bceeccf10e28d_6cfcd6386813.jpeg) is used for the binary exclusive or operation.

How many "xor-sequences" of length $k$ exist? Output the answer modulo $10^{9}+7$ .

Note if $a=[1,1]$ and $k=1$ then the answer is $2$ , because you should consider the ones from $a$ as different.

输入格式

The first line contains two integers $n$ and $k$ ( $1<=n<=100$ , $1<=k<=10^{18}$ ) — the number of given integers and the length of the "xor-sequences".

The second line contains $n$ integers $a_{i}$ ( $0<=a_{i}<=10^{18}$ ).

输出格式

Print the only integer $c$ — the number of "xor-sequences" of length $k$ modulo $10^{9}+7$ .

输入输出样例

输入 #1
5 2
15 1 2 4 8
输出 #1
13
输入 #2
5 1
15 1 2 4 8
输出 #2
5
C++ 编辑器
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