You are given a?0-indexed?integer array?nums, where?nums[i]?is a digit between?0?and?9?(inclusive).

The?triangular sum?of?nums?is the value of the only element present in?nums?after the following process terminates:

1. Let?nums?comprise of?n?elements. If?n == 1,?end?the process. Otherwise,?create?a new?0-indexed?integer array?newNums?of length?n - 1.

2. For each index?i, where?0 <= i <?n - 1,?assign?the value of?newNums[i]?as?(nums[i] + nums[i+1]) % 10, where?%?denotes modulo operator.

3. Replace?the array?nums?with?newNums.

4. Repeat?the entire process starting from step 1.

Return?the triangular sum of?nums.

?

Example 1:

Input: nums = [1,2,3,4,5]Output: 8Explanation:The above diagram depicts the process from which we obtain the triangular sum of the array.

Example 2:

Input: nums = [5]Output: 5Explanation:Since there is only one element in nums, the triangular sum is the value of that element itself.

?

Constraints:

• 1 <= nums.length <= 1000

• 0 <= nums[i] <= 9

依次遍歷即可

下面是代碼：

Runtime:?83 ms, faster than?61.97%?of?Java?online submissions for?Find Triangular Sum of an Array.

Memory Usage:?43.4 MB, less than?9.30%?of?Java?online submissions for?Find Triangular Sum of an Array.