시간 제한 | 메모리 제한 | 제출 | 정답 | 맞힌 사람 | 정답 비율 |
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1 초 | 512 MB | 38 | 9 | 6 | 20.690% |
Yuta has an undirected connected graph $G = \langle V, E \rangle$ with $n$ nodes and $n - 1$ edges. Yuta can choose some subset of edges in $E$ and remove them. It is clear that Yuta has $2^{n - 1}$ different subsets to remove.
Now, Yuta wants to know the number of ways to remove the edges which make the maximum matching size of the remaining graph $G'$ divisible by $m$. As the answer can be very large, find its remainder modulo $998\,244\,353$.
An edge set $S$ is a matching of $G = \langle V, E \rangle$ if and only if each node in $V$ is connected to at most one edge in $S$. The maximum matching of graph $G$ is defined as the matching of $G$ which has the largest size.
The first line contains two integers $n$ and $m$ ($1 \leq n \leq 5 \cdot 10^4$, $1 \leq m \leq 200$).
Then $n - 1$ lines follow, each of these lines contains two integers $u$ and $v$ which describe an edge in $G$.
Print a single line with a single integer: the answer modulo $998\,244\,353$.
4 2 1 2 2 3 3 4
3