sum_of_differences_in_array.md

Sum of differences in array

Description

Your task is to sum the differences between consecutive pairs in the array in descending order.

Example

[2, 1, 10]  -->  9

In descending order: [10, 2, 1]

Sum: (10 - 2) + (2 - 1) = 8 + 1 = 9

If the array is empty or the array has only one element the result should be 0 (Nothing in Haskell, None in Rust).

My Solution

def sum_of_differences(arr)
  arr.sort.reverse.each_cons(2).map { |a, b| a - b }.sum
end

Better/Alternative solution from Codewars

def sum_of_differences(arr)
  arr.empty? ? 0 : arr.max - arr.min
end