Count the positions where nums can be divided into a nonempty prefix and a nonempty suffix such that the prefix sum is at least the suffix sum. Return the number of valid positions. Both parts must contain at least one element.
Example 1:
Input: nums = [0,0]
Output: 1Explanation: The only split is [0] and [0]. The left sum equals the right sum, so it is valid.
Example 2:
Input: nums = [1,1]
Output: 1Explanation: The only split is [1] and [1]. Both sums are 1, so there is one valid split.
Example 3:
Input: nums = [1,2]
Output: 0Explanation: The only split is [1] and [2]. The left sum is smaller than the right sum, so this split is invalid.
Constraints:
2 <= nums.length <= 100000-100000 <= nums[i] <= 100000