#P5575. Expected Weight of Black‐White Graph Components
Expected Weight of Black‐White Graph Components
Expected Weight of Black‐White Graph Components
Given a simple, undirected, connected graph with n vertices and m edges – where the graph is either a tree (m = n-1) or a unicyclic graph (m = n) – each vertex is independently colored black with probability \(p_i\%\) and white with probability \(100-p_i\%\). We define the weight of a black‐white graph as the sum over every connected component (induced by black vertices) of the component size raised to the power \(k\), i.e.,
[ \text{weight} = \sum_{\text{black connected components } C} \left(|C|\right)^k. ]
Calculate the expected weight of the graph. Since the answer can be a rational number, output the result modulo 998244353.
Note: All formulas must be written in \(\LaTeX\) format. The input probabilities are given in percentages.
inputFormat
The first line contains three integers: n m k
(n is the number of vertices, m is the number of edges, and k is the exponent used in the weight calculation).
The following m lines each contain two integers u v
representing an edge between vertices u
and v
(1-indexed).
The last line contains n integers: p1 p2 ... pn
where p_i
is the percentage probability that the i-th vertex is colored black.
outputFormat
Output one integer: the expected weight of the black‐white graph modulo 998244353.
sample
3 2 1
1 2
2 3
50 50 50
499122178