let maxDouble = 12
let tilesInHand = 15

let all = Domino.all(up: maxDouble)
var remaining = all

let start = Domino(double: maxDouble)
remaining.remove(start)

// choose 15 random tiles
var handTiles = Set<Domino>()
while handTiles.count < tilesInHand && remaining.isEmpty == false {
    let next = remaining.randomElement()!
    handTiles.insert(next)
    remaining.remove(next)
}

let hand = Hand(dominos: handTiles)
print("====== HAND ======")
hand.print()

let trains = hand.trains(startingWith: start.trailing)
let sorted = trains.sorted { $0.path.count > $1.path.count }
if let best = sorted.first {
    print("====== BEST of \(sorted.count) ======")
    best.print()
} else {
    print("No trains starting with \(start.trailing)")
}