"""
Given an array of positive integers arr, calculate the sum of all possible odd-length subarrays.

A subarray is a contiguous subsequence of the array.

Return the sum of all odd-length subarrays of arr.

Example 1:
Input: arr = [1,4,2,5,3]
Output: 58
Explanation: The odd-length subarrays of arr and their sums are:
[1] = 1
[4] = 4
[2] = 2
[5] = 5
[3] = 3
[1,4,2] = 7
[4,2,5] = 11
[2,5,3] = 10
[1,4,2,5,3] = 15
If we add all these together we get 1 + 4 + 2 + 5 + 3 + 7 + 11 + 10 + 15 = 58

Example 2:
Input: arr = [1,2]
Output: 3
Explanation: There are only 2 subarrays of odd length, [1] and [2]. Their sum is 3.

Example 3:
Input: arr = [10,11,12]
Output: 66
"""


class Solution:
    def sumOddLengthSubarrays(self, arr) -> int:
        total = 0
        i = 1
        j = 0
        while i <= len(arr):
            while j < len(arr) and i + j <= len(arr):
                total += sum(arr[j:j + i])
                j += 1
            i += 2
            j = 0
        return total


if __name__ == "__main__":
    s = Solution()
    print(s.sumOddLengthSubarrays(arr=[1, 4, 2, 5, 3]))
