Count alternating odd/even subarrays

Given an array of numbers, count the number of subarrays where odd and even numbers alternate. Example Input: [1, 3, 2, 4] Output: 3 Explanation: Following are the odd-even alternating subarrays: [3, 2], [1, 3, 2], [3, 2, 4]. Constraints Array length is between 1 and 10^5 All numbers are positive integers. Example Input [1, 3, 2, 4] Output 3