Given an array of integers: find the first value with the largest character count when spelled out

NumericCharacterCount.swift

// I publicly share any answers to "coding challenges" I receive as a part of the interview process
// use this in an Xcode playground or the code challenge repl of choice

// Given an array of integers: find the first value with the largest character count when spelled out
// format the result like this example: "one hundred seventy-eight (178)

import UIKit

let numberFormatter = NumberFormatter()
numberFormatter.numberStyle = .spellOut // TIL this exists...
let testArray = Array(0...200)

func largestCharCount(integers: [Int]) -> String {
    var largestInt = 0
    var largestString = ""
    for i in integers {
        let testString = numberFormatter.string(from: NSNumber(value: i)) ?? "not a number"
        if testString.count > largestString.count {
            largestInt = i
            largestString = testString
        }
    }
    return "\(largestString) (\(largestInt))"
}

print ("Initial problem: \(largestCharCount(integers: testArray))")
print("")


// If there are multiple values with the same max character count, return the value that is alphabetically
// first (for ["forty one", "sixty two"] return "forty-one (41)"

func largestCharCountAlpha(integers: [Int]) -> String {
    var largestInt = 0
    var largestString = ""
    for i in integers {
        let testString = numberFormatter.string(from: NSNumber(value: i)) ?? "not a number"
        if testString.count > largestString.count {
            largestInt = i
            largestString = testString
        } else if testString.count == largestString.count {
            if testString < largestString {
                largestString = testString
                largestInt = i
            }
        }
    }
    return "\(largestString) (\(largestInt))"
}

print("Alphabetically sorted: \(largestCharCountAlpha(integers: testArray))")
print("")

// extra extra credit - use a language other than English to determine the character count

func largestCharacterCountLocale(integers: [Int], locale: Locale = Locale(identifier: "en-EN")) -> String {
    numberFormatter.locale = locale
    var largestInt = 0
    var largestString = ""
    for i in integers {
        let testString = numberFormatter.string(from: NSNumber(value: i)) ?? "not a number"
        if testString.count > largestString.count {
            largestInt = i
            largestString = testString
        } else if testString.count == largestString.count {
            if testString < largestString {
                largestString = testString
                largestInt = i
            }
        }
    }
    return "\(largestString) (\(largestInt))"
}

print("Alphabetically sorted in language other than english:")
print("Default language, English: \(largestCharacterCountLocale(integers: testArray))")
let languageArray = ["en-EN", "fr-FR", "de-DE", "it-IT", "es-ES"]
print("\nArray of languages:")
for lang in languageArray {
    numberFormatter.locale = Locale(identifier: "en-EN")
    let languageString = numberFormatter.locale.localizedString(forLanguageCode: lang) ?? "Not a language"
    print("\(languageString): \(largestCharacterCountLocale(integers: testArray, locale: Locale(identifier: lang)))")
}
print("")

// the higher order function answers, this is what they are looking for
// initial

func largestCharCountMax(_ integers: [Int]) -> String {
    func spelledOut(_ num: Int) -> String {
        return numberFormatter.string(from: NSNumber(value: num)) ?? "Not a Number?"
    }
    
    if let maxNum = integers.max(by: {spelledOut($0).count < spelledOut($1).count}) {
        return "\(spelledOut(maxNum)) (\(maxNum))"
    }
    return ""
}

numberFormatter.locale = Locale(identifier: "en-EN")
print ("Max function: \(largestCharCountMax(testArray))")
print("")

// extra credit 1

func largestCharCountMaxAlpha(_ integers: [Int]) -> String {
    func spelledOut(_ num: Int) -> String {
        return numberFormatter.string(from: NSNumber(value: num)) ?? ""
    }
    
    let alphaArray = integers.map{spelledOut($0)}
    let maxLength = alphaArray.map{$0.count}.max()
    let sortedWord = alphaArray.filter{$0.count == maxLength}.sorted().first ?? ""
    let numberForWord = numberFormatter.number(from: sortedWord) ?? 0
    return "\(sortedWord) (\(String(describing: numberForWord)))"
}

numberFormatter.locale = Locale(identifier: "en-EN")
print ("Max function alpha: \(largestCharCountMaxAlpha(testArray))")
print("")

// extra credit 2

func largestCharCountMaxAlphaLocale(_ integers: [Int], locale: Locale = Locale(identifier: "en-EN")) -> String {
    func spelledOut(_ num: Int) -> String {
        return numberFormatter.string(from: NSNumber(value: num)) ?? ""
    }
    numberFormatter.locale = locale
    
    let alphaArray = integers.map{spelledOut($0)}
    let maxLength = alphaArray.map{$0.count}.max()
    let sortedWord = alphaArray.filter{$0.count == maxLength}.sorted().first ?? ""
    let numberForWord = numberFormatter.number(from: sortedWord) ?? 0

    return "\(sortedWord) (\(numberForWord))"
}

numberFormatter.locale = Locale(identifier: "en-EN")
print ("Max function alpha locale: \(largestCharCountMaxAlphaLocale(testArray, locale: Locale(identifier: "de-DE")))")
print("")