Flatten Binary Tree to Linked List

最新推荐文章于 2022-09-06 16:04:14 发布

原创最新推荐文章于 2022-09-06 16:04:14 发布 · 160 阅读

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本文介绍了一种将二叉树结构通过特定算法展平为链表的方法。通过递归地调整二叉树节点的左右子节点指针，最终使整个二叉树结构变为一个单链表形式。该过程不会使用额外的数据结构，实现了空间复杂度O(1)。

Given a binary tree, flatten it to a linked list in-place.

For example,
Given

The flattened tree should look like:

   1
    \
     2
      \
       3
        \
         4
          \
           5
            \
             6
struct Node
{
	int val;
	Node(int v)
	{
		val = v;
		left = right = NULL;
	}
	Node *left;
	Node *right;
};

Node* visit(Node *root)
{
	if (root == NULL)
	{
		return NULL;
	}
	
	Node *tempRight = root->right;
	Node *leftNode = root;
	if (root->left != NULL)
	{
		leftNode = visit(root->left);
		root->left->left = root;
		root->right = root->left;
	}
	leftNode->right = tempRight;
	
	Node *rightNode = root;
	if (tempRight != NULL)
	{
		rightNode = visit(tempRight);
	}
	
	if (tempRight != NULL)
	{
		tempRight->left = leftNode;
	}
	
	return rightNode;
}