Given an array that contains numbers and/or other nested arrays, write an algorithm to come up with a sum of these elements, multiplied by the depth (or how many arrays deep) you are.

sumNestedArray.swift

/*
 Given an array that contains numbers and/or other nested arrays, write an algorithm to come up with a sum of these elements, multiplied by the depth (or how many arrays deep) you are.
 
 For example, what would you do with an input array that looks like:
 
 [ 2, 3, [ 9, [ 1, 2 ]], 4]
 */

import Foundation

func sumInts(in array: [Any], level: Int = 1) -> Int {
    
    let sum = array
        .flatMap { $0 as? Int }
        .reduce(0, +)
    
    let innerArrays = array
        .flatMap { $0 as? [Any] }
    
    return sum * level + (innerArrays.count > 0 ? innerArrays.reduce(0) { $0 + sumInts(in: $1, level: level + 1) } : 0 )
}

let array: [Any] = [1,[2,3],4,[2],[3,[3,[3],2],2]]

let sum = sumInts(in: array)

Great code, can we add a guard on top so that we will have simpler return statement? something like this:

guard  array.count > 0 else { return 0 }

...

return sum * level + innerArrays.reduce(0) { $0 + sumInts(in: $1, level: level + 1) }