public BTNodeWithRnd(BTNodeWithRnd nodeToCopy)
{
Data = nodeToCopy.Data;
Left = nodeToCopy.Left;
Right = nodeToCopy.Right;
Random = nodeToCopy.Random;
}
public static void TestCloneABTWithRandPointer()
{
Dictionary <int, BTNodeWithRnd> dict = new Dictionary <int, BTNodeWithRnd>();
for (int i = 0; i < 6; i++)
{
dict[i] = new BTNodeWithRnd(i);
}
dict[0].Left = dict[1];
dict[0].Right = dict[2];
dict[1].Left = dict[3];
dict[1].Right = dict[4];
dict[2].Right = dict[5];
Random rnd = new Random();
for (int i = 0; i < 5; i++)
{
dict[i].Random = dict[rnd.Next(0, 6)];
}
Console.WriteLine("The orginal tree looks like:");
PrintTree(dict[0], 'O');
CloneABTWithRandPointer clone = new CloneABTWithRandPointer();
Console.WriteLine("The cloned tree looks like:");
PrintTree(clone.GetClone(dict[0]), 'C');
}
public BTNodeWithRnd(int data, BTNodeWithRnd left, BTNodeWithRnd right, BTNodeWithRnd rnd)
{
Data = data;
Left = left;
Right = right;
Random = rnd;
}
/// <summary>
/// We will do a preorder traversal of the tree(same as doing the BFS)
/// 1. Whenever a new node is encountered, create a clone of the node and copy the original nodes fields
/// like data, left, right, random
/// 2. Make the original Nodes rnd pointer point to the nodeClone
/// 3. Now traverse from rootClone and make
/// nodeClone.Left = nodeClone.Left.Random
/// nodeClone.Right = nodeClone.Right.Random
/// nodeClone.Random = nodeClone.Random.Random
/// </summary>
/// <param name="root"></param>
/// <returns></returns>
public BTNodeWithRnd GetClone(BTNodeWithRnd root)
{
BTNodeWithRnd rootClone = null;
Queue <BTNodeWithRnd> queue = new Queue <BTNodeWithRnd>();
queue.Enqueue(root);
while (queue.Count > 0)
{
BTNodeWithRnd node = queue.Dequeue();
// 1.Whenever a new node is encountered, create a clone of the node and copy the original nodes fields
// like data, left, right, random
BTNodeWithRnd nodeClone = new BTNodeWithRnd(node);
if (rootClone == null)
{
// Set the root clone node
rootClone = nodeClone;
}
if (node.Left != null)
{
queue.Enqueue(node.Left);
}
if (node.Right != null)
{
queue.Enqueue(node.Right);
}
// 2. Make the original Nodes rnd pointer point to the nodeClone
node.Random = nodeClone;
}
// 3. Now traverse the clone and make all the node pointers point to the cloned nodes
queue.Enqueue(rootClone);
while (queue.Count > 0)
{
BTNodeWithRnd nodeClone = queue.Dequeue();
if (nodeClone.Left != null)
{
nodeClone.Left = nodeClone.Left.Random;
queue.Enqueue(nodeClone.Left);
}
if (nodeClone.Right != null)
{
nodeClone.Right = nodeClone.Right.Random;
queue.Enqueue(nodeClone.Right);
}
if (nodeClone.Random != null)
{
nodeClone.Random = nodeClone.Random.Random;
}
}
return(rootClone);
}
public static void PrintTree(BTNodeWithRnd root, char position)
{
if (root != null)
{
Console.WriteLine("{0} : {1}, rnd{2}", position, root.Data, ((root.Random != null)?root.Random.ToString() :"null"));
PrintTree(root.Left, 'L');
PrintTree(root.Right, 'R');
}
}
