Hide
Problem D
Count Doubles
Given an array of $n$ positive integers and an integer $m$, count how many contiguous subarrays of exactly $m$ elements have two or more even values.
For example, given the subarray 1 2 3 4 5 6 7 8 and $m = 3$, the three subarrays 2 3 4, 4 5 6, and 6 7 8 each have at least two even values.
Input
The first line of input consists of the size $1\leq n\leq 10^3$ of the array, followed by $m<n$, the subarray size. Then $n$ positive integers, each at most $10^3$, follow on the second line.
Output
Output how many contiguous subarrays of $m$ elements have at least two even elements.
| Sample Input 1 | Sample Output 1 |
|---|---|
8 3 1 2 3 4 5 6 7 8 |
3 |
| Sample Input 2 | Sample Output 2 |
|---|---|
9 4 1 2 3 5 7 8 9 11 5 |
0 |
