Number of Zero-Filled Subarrays

You are given an integer array nums, return the number of subarrays filled with 0.

A subarray is a contiguous non-empty sequence of elements within an array.

Example 1:

Input: nums = [1,3,0,0,2,0,0,4]

Output: 6

Explanation: There are 4 occurrences of [0] as a subarray. There are 2 occurrences of [0,0] as a subarray. There is no occurrence of a subarray with a size more than 2 filled with 0. Therefore, we return 6.

Example 2:

Input: nums = [0,0,0,2,0,0]

Output: 9

Explanation: There are 5 occurrences of [0] as a subarray. There are 3 occurrences of [0,0] as a subarray. There is 1 occurrence of [0,0,0] as a subarray. There is no occurrence of a subarray with a size more than 3 filled with 0. Therefore, we return 9.

Example 3:

Input: nums = [2,10,2019]

Output: 0

Explanation: There is no subarray filled with 0. Therefore, we return 0.

Constraints:

• 1 <= nums.length <= 100,000
• -1,000,000,000 <= nums[i] <= 1,000,000,000