2562.Find the series of the array

topic：

2562.Find the series of the array.md

Thought：

This question andquiz4very similar，都是Double pointer。
I made a mistake when I did this question，When calculating the right pointer, the negative index is calculatedright = -left + 1，It is difficult to calculate the relationship between positive indexes，So replacedright = len(nums) - 1 - left。

Code：

class Solution:
    def findTheArrayConcVal(self, nums: List[int]) -> int:
        sums = 0
        for left in range(len(nums)):
            right = len(nums) - 1 - left
            if left == right:
                sums += nums[left]
                break
            elif left < right:
                sums += int(str(nums[left]) + str(nums[right]))
        return sums