题目描述
Problem Background
Always remember you are human, not an animal.
Before eating corn and tomato炖山羊肉, you need to answer a question.
Problem Description
Given \( n, m \), a sequence of integers is considered "valid" if (let the sequence be \( s \)):
- \( s \) has a length of \( m \).
- \( \forall i \in [1, m], s_i \in [1, n] \).
- \( \forall i \in [2, m], |s_i - s_{i-1}| = 1 \).
Given a permutation \( p \) of the range \([1, n]\), and define the "corresponding sequence" \( s' \) of a sequence \( s \): \( s' \) has the same length as \( s \); let its length be \( l \), then \( \forall i \in [1, l], s'_i = p_{s_i} \).
Given \( k \), find the sum of all elements in the \( k \)-th smallest corresponding sequence among all distinct valid integer sequences, modulo \( 2^{32} \).
If there is no \( k \)-th smallest corresponding sequence, output \(-1\).
Input Format
The first line contains three integers \( n, m, k \).
The second line contains \( n \) integers representing \( p \).
Output Format
A single integer representing the answer.
Sample Input and Output
Sample Input #1
10 6 3
5 7 4 3 6 2 10 8 9 1
Sample Output #1
38
Sample Input #2
2 5 2
1 2
Sample Output #2
8
Sample Input #3
2 114514 1
2 1
Sample Output #3
171771
Sample Input #4
3 1000000000000000000 3
2 1 3
Sample Output #4
2065039361
Notes
The input file is large, please use appropriate input methods.
Sample Explanation
For Sample #1, among all distinct valid integer sequences' corresponding sequences, the first three smallest in lexicographical order are:
$$\{1,9,1,9,1,9\}$$
$$\{1,9,1,9,8,9\}$$
$$\{1,9,1,9,8,10\}$$
So the answer is \( 1+9+1+9+8+10=38 \).
For Sample #2, among all distinct valid integer sequences' corresponding sequences, the first two smallest in lexicographical order are:
$$\{1,2,1,2,1\}$$
$$\{2,1,2,1,2\}$$
So the answer is \( 2+1+2+1+2=8 \).
Data Size
| Subtask | \( n \le \) | \( m \le \) | \( k \le \) | Score |
|---|---|---|---|---|
| 1 | 20 | 10 | \( 10^{18} \) | 5 |
| 2 | 70 | 70 | \( 10^{18} \) | 15 |
| 3 | 100 | 300 | \( 10^{18} \) | 20 |
| 4 | \( 10^4 \) | \( 10^4 \) | \( 10^{18} \) | 15 |
| 5 | \( 10^4 \) | \( 10^{18} \) | \( 10^{18} \) | 10 |
| 6 | \( 10^6 \) | \( 10^{18} \) | 1 | 5 |
| 7 | \( 2 \times 10^7 \) | \( 10^{18} \) | \( 10^{18} \) | 30 |
For \( 100\% \) of the data, \( 1 \le n \le 2 \times 10^7 \), \( 2 \le m \le 10^{18} \), \( 1 \le k \le 10^{18} \).
Special Scoring Method
This problem has subtask dependencies, specifically:
- For subtasks \( i \in \{1, 6\} \), you only need to solve subtask \( i \) to get the score for subtask \( i \).
- For subtasks \( i \in \{2, 3, 4, 5, 7\} \), you need to solve all subtasks \( j \in [1, i] \) to get the score for subtask \( i \).
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分