2270 - Number of Ways to Split Array.

Medium

You are given a 0-indexed integer array nums of length n.

nums contains a valid split at index i if the following are true:

• The sum of the first i + 1 elements is greater than or equal to the sum of the last n - i - 1 elements.

• There is at least one element to the right of i. That is, 0 <= i < n - 1.

Return the number of valid splits in nums.

Example 1:

Input: nums = 10,4,-8,7

Output: 2

Explanation: There are three ways of splitting nums into two non-empty parts:

• Split nums at index 0. Then, the first part is 10, and its sum is 10. The second part is 4,-8,7, and its sum is 3. Since 10 >= 3, i = 0 is a valid split.

• Split nums at index 1. Then, the first part is 10,4, and its sum is 14. The second part is -8,7, and its sum is -1. Since 14 >= -1, i = 1 is a valid split.

• Split nums at index 2. Then, the first part is 10,4,-8, and its sum is 6. The second part is 7, and its sum is 7. Since 6 < 7, i = 2 is not a valid split. Thus, the number of valid splits in nums is 2.

Example 2:

Input: nums = 2,3,1,0

Output: 2

Explanation: There are two valid splits in nums:

• Split nums at index 1. Then, the first part is 2,3, and its sum is 5. The second part is 1,0, and its sum is 1. Since 5 >= 1, i = 1 is a valid split.

• Split nums at index 2. Then, the first part is 2,3,1, and its sum is 6. The second part is 0, and its sum is 0. Since 6 >= 0, i = 2 is a valid split.

Constraints:

• <code>2 <= nums.length <= 10⁵</code>

• <code>-10⁵<= numsi<= 10⁵</code>