A9978. Duff in Beach
编程题
普及/提高-
知识点
题目描述
While Duff was resting in the beach, she accidentally found a strange array $b_{0},b_{1},...,b_{l-1}$ consisting of $l$ positive integers. This array was strange because it was extremely long, but there was another (maybe shorter) array, $a_{0},...,a_{n-1}$ that $b$ can be build from $a$ with formula: $b_{i}=a_{i\ mod\ n}$ where $a\ mod\ b$ denoted the remainder of dividing $a$ by $b$ .
Duff is so curious, she wants to know the number of subsequences of $b$ like $b_{i1},b_{i2},...,b_{ix}$ ( $0<=i_{1}<i_{2}<...<i_{x}<l$ ), such that:
- $1<=x<=k$
- For each $1<=j<=x-1$ , 
- For each $1<=j<=x-1$ , $b_{ij}<=b_{ij+1}$ . i.e this subsequence is non-decreasing.
Since this number can be very large, she want to know it modulo $10^{9}+7$ .
Duff is not a programmer, and Malek is unavailable at the moment. So she asked for your help. Please tell her this number.
Duff is so curious, she wants to know the number of subsequences of $b$ like $b_{i1},b_{i2},...,b_{ix}$ ( $0<=i_{1}<i_{2}<...<i_{x}<l$ ), such that:
- $1<=x<=k$
- For each $1<=j<=x-1$ , 
- For each $1<=j<=x-1$ , $b_{ij}<=b_{ij+1}$ . i.e this subsequence is non-decreasing.
Since this number can be very large, she want to know it modulo $10^{9}+7$ .
Duff is not a programmer, and Malek is unavailable at the moment. So she asked for your help. Please tell her this number.
输入格式
The first line of input contains three integers, $n,l$ and $k$ ( $1<=n,k$ , $n×k<=10^{6}$ and $1<=l<=10^{18}$ ).
The second line contains $n$ space separated integers, $a_{0},a_{1},...,a_{n-1}$ ( $1<=a_{i}<=10^{9}$ for each $0<=i<=n-1$ ).
The second line contains $n$ space separated integers, $a_{0},a_{1},...,a_{n-1}$ ( $1<=a_{i}<=10^{9}$ for each $0<=i<=n-1$ ).
输出格式
Print the answer modulo $1000000007$ in one line.
输入输出样例
输入 #1
3 5 3 5 9 1
输出 #1
10
输入 #2
5 10 3 1 2 3 4 5
输出 #2
25
说明/提示
In the first sample case, . So all such sequences are: , , , , , , , ,  and .