2025-08-09 13:17:16 +0000 UTC

class Solution:
    def sumOddLengthSubarrays(self, arr: List[int]) -> int:
        length = len(arr)
        answer = 0
        for i, num in enumerate(arr):
            left, right = i, length - i - 1
            odd_left, odd_right = (left // 2) + 1, (right // 2) + 1
            even_left, even_right = (left + 1) // 2, (right + 1) // 2
            sub_count = (odd_left * odd_right) + (even_left * even_right)
            answer += num * sub_count
        return answer