[Playground]Reversing_LinkedList.swift

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

import Cocoa

/* Node class implementation */

class Node
{
    var data:String?
    var link:Node?
    
    init(data:String?, link:Node? = nil)
    {
        self.data = data
        self.link = link
    }
}


/* Helper functions */

func printList(node:Node?)
{
    var l:Node? = node
    
    println("\nPrinting --------");
    while l{
        println("\(l!.data)")
        l = l!.link
    }

}

func reverseList(var node:Node?)->(Node?)
{
    var new_root:Node?
    
    while node{
        var next = node!.link
        node!.link = new_root
        
        new_root = node
        node = next
    }
    
    return new_root
}


/* Setup the list */

var d = Node(data:"d");
var c = Node(data:"c", link:d);
var b = Node(data:"b", link:c);
var a = Node(data:"a", link:b);


/* Print and reverse */

printList(a);
var r = reverseList(a);
printList(r)