P25798 [AtCoder] We Love Forest
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题目描述

Problem Statement

We have a graph G with N vertices numbered 1 through N and 0 edges. You are given sequences $u=(u_1,u_2,\ldots,u_M),v=(v_1,v_2,\ldots,v_M)$ of length M.
You will perform the following operation (N-1) times.

  • Choose $i (1 \leq i \leq M)$ uniformly at random. Add to G an undirected edge connecting Vertices u_i and v_i.

Note that the operation above will add a new edge connecting Vertices u_i and v_i even if G already has one or more edges between them. In other words, the resulting G may contain multiple edges.
For each $K=1,2,\ldots,N-1,$ find the probability, modulo 998244353, that G is a forest after the K-th operation.

What is a forest?
An undirected graph without a cycle is called a forest. A forest is not necessarily connected.

Definition of probability modulo 998244353
We can prove that the sought probability is always a rational number. Moreover, under the Constraints of this problem, it is guaranteed that, when the sought probability is represented by an irreducible fraction $\frac{y}{x}, x$ is indivisible by 998244353.
Then, we can uniquely determine an integer z between 0 and 998244352 (inclusive) such that xz $\equiv y \pmod{998244353}$. Print this z.

Input

Input is given from Standard Input in the following format:
N M
u_1 v_1
$\vdots$
u_M v_M

Output

Print N-1 lines. The i-th line should contain the probability, modulo 998244353, that G is a forest after the i-th operation.

Constraints

  • $2 \leq N \leq 14$
  • $N-1 \leq M \leq 500$
  • $1 \leq u_i,v_i \leq N$
  • $u_i\neq v_i$
  • All values in input are integers.

Sample Input 1

3 2
1 2
2 3

Sample Output 1

1
499122177

Let us denote by (u, v) the edge connecting Vertices u and v.
After the 1-st operation, G will have:

  • Edge (1, 2) with a probability of 1/2;
  • Edge (2, 3) with a probability of 1/2.

In both cases, G is a forest, so the answer for K=1 is 1.
After the 2-nd operation, G will have:

  • Edges (1, 2) and (1, 2) with a probability of 1/4;
  • Edges (2, 3) and (2, 3) with a probability of 1/4;
  • Edges (1, 2) and (2, 3) with a probability of 1/2.

G is a forest only when G has Edges (1, 2) and (2, 3). Therefore, the sought probability is 1/2; when represented modulo 998244353, it is 499122177, which should be printed.

Sample Input 2

4 5
1 2
1 2
1 4
2 3
2 4

Sample Output 2

1
758665709
918384805

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
3 2 1 2 2 3
样例输出
1 499122177