03_waysToSplitArray.py

'''Time Complexity O(n)
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.'''
from typing import *
class Solution:
  def waysToSplitArray(self, nums: List[int]) -> int:
    total=0
    preFix=0 
    ans=0     
    for i in nums:
      total+=i
    for i in range(len(nums)-1):
      preFix+=nums[i]
      total=total-nums[i]
      if preFix>=total:
        ans+=1
    return ans