1724.
Rikka with Match
时间限制 7000 ms
内存限制 256 MB
As we know, Rikka is poor at math. Yuta is worrying about this situation, so he gives Rikka some math tasks to practice. There is one of them:
Yuta has an undirected connected graph $G=\langle V,E \rangle$ with $n$ nodes and $n-1$ edges. Yuta can choose some edges in $E$ and remove them. It is clear that Yuta has $2^{n-1}$ different ways to remove.
Now, Yuta want to know the number of ways to remove the edges which make the maximum matching size of the remaining graph $G'$ is divisible by $m$.
It is too difficult for Rikka. Can you help her?
An edge set $S$ is a match of $G=\langle V,E \rangle$ if and only if each nodes in $V$ connects to at most one edge in $S$. The maximum matching of graph $G$ is defined as the match of $G$ with the largest size.
输入数据
输出数据
For each testcase, print a single line with a single number -- the answer modulo $998244353$.
样例输入
复制
1
4 2
1 2
2 3
3 4
\n
· \n
· \n
· \n
· \n