LeetCode 2221. Find Triangular Sum of an Array

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

依次遍历即可

下面是代码：

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.