KiyoshiNoZundokoBushi.swift

import Foundation

enum Phrase: Int, CustomStringConvertible {
    case zun = 0
    case doko = 1
    
    var description: String {
        switch self {
        case .zun:
            return "ずん"
        case .doko:
            return "どこ"
        }
    }
}

func kiyoshiNoZundokoBushi() {
   
    for _ in 0..<INT_MAX {
        let phrases: [Phrase] = Array(0..<5).flatMap({ _ in Phrase(rawValue: Int(arc4random_uniform(2))) })
        let string: String =  phrases.reduce("", { (result, phrase)  in
            return result + phrase.description
        })
        
        if phrases == [.zun, .zun, .zun, .zun, .doko] {
            print(string + "きよし！")
            break
        } else {
            print(string)
        }
    }
    
}

kiyoshiNoZundokoBushi()