Problem-Solving Notes (4)--transforming the two-dollar lookup tree into a sorted doubly linked list

Problem Description: Enter a two-dollar lookup tree to convert the two-dollar lookup tree into a sorted doubly linked list. Requires that no new nodes be created, only the pointer is adjusted.
10
/ /
6 14
/ / / /
4 8 12 16
Convert to doubly linked list

4=6=8=10=12=14=16.

Idea: Using recursive thought to solve, adjust the left and right sub-tree of a node, adjust the left pointer of the node to the Zuozi's maximum node, and then point to the smallest node of the right sub-tree.

The code is as follows:

Bstreenode * Convert (bstreenode *node)
{
	if (node = = null)
		return null;
	Bstreenode *leftmax,*rightmin;
	Leftmax = node->left;    
	Rightmin = node->right;
	Find the maximum node of Zuozi while
	(Leftmax! = NULL && leftmax->right! = null)
		Leftmax = leftmax->right;
	Find the smallest node of the right subtree while
	(rightmin! = NULL && Rightmin->left! = null)
		rightmin = rightmin->left;
	Recursive solution to
	Convert (node->right); 
	Convert (node->left);
	Connect the same root node of the left and right subtree, but only with the sibling relationship
	if (leftmax! = NULL)
		leftmax->right = node;
	if (rightmin! = NULL)
		rightmin->left = node;
	Node->left = Leftmax;
	Node->right = rightmin;
	return node;
}

In the test, we need to build a two-fork search tree, and the code to build and traverse the binary tree is given below.

struct Bstreenode
{
	int value;
	Bstreenode *left;
	Bstreenode *right;
};
Bstreenode * Insert (bstreenode *p, int x)
{
	if (p = = NULL)
	{
		p = new Bstreenode;
		P->value = x;
		P->left = NULL;
		P->right = NULL;
	}
	else
	{
		if (P->value > x)
			p->left = Insert (p->left, x);
		if (P->value < x)
			p->right = Insert (p->right, x);
	}
	return p;
}
void Traverse (Bstreenode *p)//middle order traversal
{
	if (p = = NULL)
		return;
	Traverse (p->left);
	cout<<p->value<< ";
	Traverse (p->right);
}

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