Given an undirected connected graph of nnn vertices and n1n-1n1 edges, where nnn is guaranteed to be odd. You want to divide all the n1n-1n1 edges to n12frac{n-1}{2}2n1 groups under following constrai
Given an undirected connected graph of nnn vertices and n−1n-1n−1 edges, where nnn is guaranteed to be odd. You want to divide all the n−1n-1n−1 edges to n−12frac{n-1}{2}2n−1 groups under following constraints: There are exactly 2 edges in each group The 2 edges in the same group share a common vertex Determine the number of valid dividing schemes modulo 998244353998244353998244353. Two schemes are considered different if there are 2 edges that are in the same group in one scheme but not in the same group in the other scheme.
（图片来源网络，侵删）
