2025-08-20 15:28:35 +0000 UTC

class Solution:
    def alternateDigitSum(self, n: int) -> int:
        sign = 1
        count = 0
        res = 0
        while n > 0: 
            res += (n % 10) * sign
            sign *= -1
            count += 1
            n //= 10
        if count % 2 == 0:
            return -res
        return res