twelve-days.swift

//: Playground - noun: a place where people can play

import UIKit

func wordFromNum(_ num: Int) -> String {
    let suffixes = ["th","st","nd","rd","th"]
    var idx = min(num % 10, suffixes.count-1)
    let tens = num % 100
    if tens > 10 && tens < 14 {
        idx = 0
    }
    return "\(num)\(suffixes[idx])"
}

let phrases = [
    "a Partridge in a Pear Tree",
    "2 Turtle Doves",
    "3 French Hens",
    "4 Calling Birds",
    "** FIIIIIVE GOOOOLDEN RIIIIIIIINGS! **",
    "6 Geese a Laying",
    "7 Swans a Swimming",
    "8 Maids a Milking",
    "9 Ladies Dancing",
    "10 Lords a Leaping",
    "11 Pipers Piping",
    "12 Drummers Drumming"
]

for idx in (0...11) {
    var verse = "On the \(wordFromNum(idx+1)) day of Christmas\nmy true love sent to me:\n"
    for reversedIdx in (0...idx).reversed() {
        if reversedIdx == 0 && idx > 0 {
            verse += "and "
        }
        verse += phrases[reversedIdx] + "\n"
    }
    print("\(verse)")
}