题目描述
Problem Description
Legend has it that a long, long time ago, there was a labeled directed acyclic graph with $n$ vertices. Each edge had a color, which was one of $k$ different colors. This graph satisfied the following properties:
- Each vertex had at most one outgoing edge.
- The number of incoming edges for each vertex was in the set $S$.
For some reason, you want to know the number of such graphs. Since there might be many such graphs, you only need to output the answer modulo $998244353$.
Two graphs are considered different if and only if there exists a directed edge from vertex $a$ to vertex $b$ that appears in exactly one graph, or it appears in both graphs but with different colors.
Input Format
The first line contains three positive integers $n, k, |S|$.
The second line contains $|S|$ distinct non-negative integers in ascending order, representing the elements in set $S$.
Output Format
Output a single integer in the range $[0, 998244352]$, representing the number of valid graphs modulo $998244353$.
Sample Input and Output
Input Sample #1
3 1 2
0 1
Output Sample #1
13
Input Sample #2
8 2 3
0 2 3
Output Sample #2
7497953
Input Sample #3
3000 2 3
0 1 3
Output Sample #3
500207304
Input Sample #4
10000000 3 2
0 3
Output Sample #4
238588124
Input Sample #5
876543210 233 4
0 1 2 3
Output Sample #5
467638557
Notes
Sample 1 Explanation
There are $13$ valid graphs, where $a \to b$ represents a directed edge from $a$ to $b$:
- No edges
- $1 \to 2$
- $2 \to 1$
- $1 \to 3$
- $3 \to 1$
- $2 \to 3$
- $3 \to 2$
- $1 \to 2 \to 3$
- $1 \to 3 \to 2$
- $2 \to 1 \to 3$
- $2 \to 3 \to 1$
- $3 \to 1 \to 2$
- $3 \to 2 \to 1$
Data Range
The data is divided into $7$ subtasks.
- Subtask $1$ ($5$ points): $n \leq 8$.
- Subtask $2$ ($10$ points): $n \leq 5000$.
- Subtask $3$ ($30$ points): $n \leq 10^5$.
- Subtask $4$ ($20$ points): $n \leq 10^7$.
- Subtask $5$ ($15$ points): $n \leq 10^8$.
- Subtask $6$ ($10$ points): $S = \{0, 1\}$.
- Subtask $7$ ($10$ points): No special restrictions.
For $100\%$ of the data, $1 \le n \le 9 \times 10^8$, $1 \le k \le 10^7$, $S \neq \varnothing$, $S \subseteq \{0, 1, 2, 3\}$.
By: fjzzq2002
Source: 2019 Training Team Mutual Test Day 5
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分