Daily LeetCode Exercise - Running Sum of 1d Array

Given an array nums. We define a running sum of an array as runningSum[i] = sum(nums[0]…nums[i]).

Return the running sum of nums.

Example 1:

Input: nums = [1,2,3,4]

Output: [1,2,4]

Explanation: Running sum is obtained as follows: [1, 1+2, 1+2+3, 1+2+3+4].

Example 2:

Input: nums = [1,1,1,1,1]

Output: [1,2,3,4,5]

Explanation: Running sum is obtained as follows: [1, 1+1, 1+1+1, 1+1+1+1, 1+1+1+1+1].

Example 3:

Input: nums = [3,1,2,10,1]

Output: [3,4,6,16,17]

def running_sum(nums)
  nums.each_with_index do |num, i|
    if nums[i + 1]
      nums[i + 1] = num + nums[i + 1]
    end
  end
  nums
end

Kevin