Traversing the tree in swift.

Traverse.swift

class Node<T> {
    var value:T
    var next: Node?
    var previous: Node?
    
    init(value: T) {
        self.value = value
        self.next = nil
        self.previous = nil
    }
}

func traverse (head: Node<Int>?) {
    var current: Node<Int>? = head
    while let curr = current {
        print(String(describing: (curr.value)))
        current = curr.next
    }
}