BinarySearch 0914 Number of Sublists With Odd Sum

Problem statement

https://binarysearch.com/problems/Number-of-Sublists-With-Odd-Sum/

Solution

Equal to Leetcode 0974. Subarray Sums Divisible by K.

Complexity

It is O(n) for time and O(1) for space.

Code

class Solution:
    def solve(self, nums):
        acc = [0] + list(accumulate(nums))
        cnt = Counter()
        for x in acc:
            cnt[x%2] += 1
            
        return (cnt[0] * cnt[1]) % (10**9 + 7)