题目描述
Problem Statement
Given are a sequence of $N positive integers A_1, A_2, \ldots, A_N$, and a positive integer K.
Find the number of non-empty contiguous subsequences in A such that the remainder when dividing the sum of its elements by K is equal to the number of its elements. We consider two subsequences different if they are taken from different positions, even if they are equal sequences.
Input
Input is given from Standard Input in the following format:
N K
$A_1 A_2 \cdots A_N$
Output
Print the number of subsequences that satisfy the condition.
Constraints
- All values in input are integers.
- $1 \leq N \leq 2\times 10^5$
- $1 \leq K \leq 10^9$
- $1 \leq A_i \leq 10^9$
Sample Input 1
5 4
1 4 2 3 5
Sample Output 1
4
Four sequences satisfy the condition: (1), (4,2), (1,4,2), and (5).
Sample Input 2
8 4
4 2 4 2 4 2 4 2
Sample Output 2
7
(4,2) is counted four times, and (2,4) is counted three times.
Sample Input 3
10 7
14 15 92 65 35 89 79 32 38 46
Sample Output 3
8
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分