Problem URL: Difference between element sum and digit sum of an array

We will calculate the sum of every digit in the array and subtract it from the sum of the array.

class Solution:
    def differenceOfSum(self, nums: List[int]) -> int:
        numsArrayAsString = list(''.join(map(str, nums)))
        numsArrayDigits = list(map(int, numsArrayAsString))
        digitSum = sum(numsArrayDigits)
        elementSum = sum(nums)
        return elementSum - digitSum

Time complexity: O(n)
Space complexity: O(n)

We can achieve the same result with a single line.

class Solution:
    def differenceOfSum(self, nums: List[int]) -> int:
        return sum(nums) - sum(map(int, list(''.join(map(str, nums)))))