// Given array of 2-tuples, return two arrays
func unzip<T, U>(array: [(T, U)]) -> ([T], [U]) {
    var t = Array<T>()
    var u = Array<U>()
    for (a, b) in array {
        t.append(a)
        u.append(b)
    }
    return (t, u)
}

// Given sequence of 2-tuples, return two arrays
func unzip<T, U>(sequence: SequenceOf<(T, U)>) -> ([T], [U]) {
    var t = Array<T>()
    var u = Array<U>()
    for (a, b) in sequence {
        t.append(a)
        u.append(b)
    }
    return (t, u)
}

// Given array of 3-tuples, return three arrays
func unzip3<T, U, V>(array: [(T, U, V)]) -> ([T], [U], [V]) {
    var t = Array<T>()
    var u = Array<U>()
    var v = Array<V>()
    for (a, b, c) in array {
        t.append(a)
        u.append(b)
        v.append(c)
    }
    return (t, u, v)
}

// Given sequence of 3-tuples, return three arrays
func unzip3<T, U, V>(sequence: SequenceOf<(T, U, V)>) -> ([T], [U], [V]) {
    var t = Array<T>()
    var u = Array<U>()
    var v = Array<V>()
    for (a, b, c) in sequence {
        t.append(a)
        u.append(b)
        v.append(c)
    }
    return (t, u, v)
}

let elements = [(0, "Zero"), (1, "One"), (2, "Two")]
let (numbers, strings) = unzip(elements)
println("numbers = \(numbers)")
println("strings = \(strings)")
// numbers = [0, 1, 2]
// strings = ["Zero", "One", "Two]


let elements3 = [(0, "Zero", "A"), (1, "One", "B"), (2, "Two", "C")]
let (numbers3, strings3, letters3) = unzip3(elements3)
println("numbers3 = \(numbers3)")
println("strings3 = \(strings3)")
println("letters3 = \(letters3)")
// numbers3 = [0, 1, 2]
// strings3 = ["Zero", "One", "Two]
// letters3 = ["A", "B", "C"]