Convert a binary search tree into a sorted two-way linked list

[Cpp]
<Span style = "color: rgb (51, 51, 51); font-family: Arial; font-size: 14px; line-height: 26px; "> <strong> converts a binary search tree into a sorted two-way linked list
</Strong> question:
Enter a binary search tree and convert it into a sorted two-way linked list.
You must not create any new node. You only need to adjust the pointer point.

10
//
6 14
////
4 8 12 16

Convert to a two-way linked list
4 = 6 = 8 = 10 = 12 = 14 = 16. </Span>
[Cpp]
# Include <iostream>
Using namespace std;
 
Class Node {
Public:
Int data;
Node * left;
Node * right;

Node (int d = 0, Node * lr = 0, Node * rr = 0): data (d), left (lr), right (rr ){}
};
 
Node * create ()
{
Node * root;
Node * p4 = new Node (4 );
Node * p8 = new Node (8 );
Node * p6 = new Node (6, p4, p8 );

Node * p12 = new Node (12 );
Node * p16 = new Node (16 );
Node * p14 = new Node (14, p12, p16 );
 
Node * p11 = new Node (11 );
Node * p13 = new Node (13 );
P12-> left = p11;
P12-> right = p13;
 
Node * p15 = new Node (15 );
Node * p19 = new Node (19 );
 
Node * p18 = new Node (18 );
Node * p20 = new Node (20 );
P16-> left = p15;
P16-> right = p19;

P19-> left = p18;
P19-> right = p20;
Node * p10 = new Node (10, p6, p14 );
Root = p10;

Return root;
}
 
Void BTreeToLink (Node * & node, int curIndex)
{
Node * ptr;
If (node-> left)
{
BTreeToLink (node-> left, curIndex + 1 );
Node-> left-> right = node;
}
If (node-> right)
{
BTreeToLink (node-> right, curIndex + 1 );
 
Ptr = node-> right;
While (ptr-> left) // move to the node with the smallest value
Ptr = ptr-> left;
Ptr-> left = node; // connect the node
Node-> right = ptr;
While (node-> right) // points to the largest node
Node = node-> right;
}
}
Int main (int argc, char * argv [])
{
 
Node * root = create ();
Node * ptr = NULL;
BTreeToLink (root, 0 );
 
Ptr = root;
While (ptr-> left! = NULL)
{
Ptr = ptr-> left;
}
 
While (ptr)
{
Cout <ptr-> data <endl;
Ptr = ptr-> right;
}
Return 0;
}