Tree Coloring

4000ms

524288K

Description:

You are given a rooted tree consisting of $$$n$$$ vertices numbered from $$$1$$$ to $$$n$$$. The root of the tree is the vertex $$$1$$$.

You have to color all vertices of the tree into $$$n$$$ colors (also numbered from $$$1$$$ to $$$n$$$) so that there is exactly one vertex for each color. Let $$$c_i$$$ be the color of vertex $$$i$$$, and $$$p_i$$$ be the parent of vertex $$$i$$$ in the rooted tree. The coloring is considered beautiful if there is no vertex $$$k$$$ ($$$k > 1$$$) such that $$$c_k = c_{p_k} - 1$$$, i. e. no vertex such that its color is less than the color of its parent by exactly $$$1$$$.

Calculate the number of beautiful colorings, and print it modulo $$$998244353$$$.

Input:

The first line contains one integer $$$n$$$ ($$$2 \le n \le 250000$$$) — the number of vertices in the tree.

Then $$$n-1$$$ lines follow, the $$$i$$$-th line contains two integers $$$x_i$$$ and $$$y_i$$$ ($$$1 \le x_i, y_i \le n$$$; $$$x_i \ne y_i$$$) denoting an edge between the vertex $$$x_i$$$ and the vertex $$$y_i$$$. These edges form a tree.

Output:

Print one integer — the number of beautiful colorings, taken modulo $$$998244353$$$.

Sample Input:

Sample Output:

Sample Input:

Sample Output:

Sample Input:

Sample Output:

955085064

Informação

Provedor Codeforces

Código CF1613F