A14499. Cyclic Sum
编程题
普及/提高-
知识点
题目描述
The first line contains three integers $n$ , $m$ , and $k$ ( $1 \leq n, m, k \leq 2 \cdot 10^5$ , $k = 1$ or $k$ is a prime number).
The second line contains $n$ integers $a_1, a_2, \ldots, a_n$ ( $0 \leq a_i \leq 2 \cdot 10^5$ ).
The second line contains $n$ integers $a_1, a_2, \ldots, a_n$ ( $0 \leq a_i \leq 2 \cdot 10^5$ ).
输入格式
Output an integer denoting the number of different segments in $b$ where the sum of elements in the segment is divisible by $k$ , modulo $10^9 + 7$ .
输出格式
In the first example, all valid segments are $[1,4]$ , $[2, 3]$ , $[3, 5]$ , and $[4, 2]$ .
In the second example, one of the valid segments is $[1, 5]$ .
In the second example, one of the valid segments is $[1, 5]$ .
输入输出样例
输入 #1
5 1 5 1 2 3 4 3
输出 #1
4
输入 #2
5 1 5 1 2 3 4 5
输出 #2
5
输入 #3
5 4 5 1 2 3 4 5
输出 #3
125
说明/提示
In the first example, all valid segments are $[1,4]$ , $[2, 3]$ , $[3, 5]$ , and $[4, 2]$ .
In the second example, one of the valid segments is $[1, 5]$ .
In the second example, one of the valid segments is $[1, 5]$ .