LeetCode（算法）- 426. 将二叉搜索树转化为排序的双向链表

Posted 2022-04-30 放羊的牧码

题目链接：点击打开链接

题目大意：略

解题思路：略

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AC 代码

• Java

/*
// Definition for a Node.
class Node 
    public int val;
    public Node left;
    public Node right;

    public Node() 

    public Node(int _val) 
        val = _val;
    

    public Node(int _val,Node _left,Node _right) 
        val = _val;
        left = _left;
        right = _right;
    
;
*/

class Solution 
    Node pre, head;
    public Node treeToDoublyList(Node root) 
        if(root == null) return null;
        dfs(root);
        head.left = pre;
        pre.right = head;
        return head;
    
    void dfs(Node cur) 
        if(cur == null) return;
        dfs(cur.left);
        if(pre != null) pre.right = cur;
        else head = cur;
        cur.left = pre;
        pre = cur;
        dfs(cur.right);
    

• C++

/*
// Definition for a Node.
class Node 
public:
    int val;
    Node* left;
    Node* right;

    Node() 

    Node(int _val) 
        val = _val;
        left = NULL;
        right = NULL;
    

    Node(int _val, Node* _left, Node* _right) 
        val = _val;
        left = _left;
        right = _right;
    
;
*/

class Solution 
public:
    Node* treeToDoublyList(Node* root) 
        if(root == nullptr) return nullptr;
        dfs(root);
        head->left = pre;
        pre->right = head;
        return head;
    
private:
    Node *pre, *head;
    void dfs(Node* cur) 
        if(cur == nullptr) return;
        dfs(cur->left);
        if(pre != nullptr) pre->right = cur;
        else head = cur;
        cur->left = pre;
        pre = cur;
        dfs(cur->right);
    
;