[Leetcode] Convert Sorted List to Binary Search Tree

Convert Sorted List to Binary Search Tree

Given a singly linked list where elements is sorted in ascending order, convert it to a height balanced BST.

Problem Solving Ideas:

Test instructions is a binary lookup tree that constructs an ordered list. The method of finding the middle node is using a double-pointer approach. Note that we also need to save the previous node of the middle node, so that a linked list can be divided into two linked lists. Note that the 38 line is to restore the linked list to its original appearance.

/** * Definition for singly-linked list. * struct ListNode {* int val; * ListNode *next; * ListNode (int x): Val (x), Next (NULL) {} *}; *//** * Definition for a binary tree node. * struct TreeNode {* int val; * TreeNode *left; * TreeNode *right; * TreeNode (int x): Val (x), left (NULL) , right (NULL) {}};        */class Solution {public:treenode* Sortedlisttobst (listnode* head) {if (head = = null) {return null;        } listnode* Myhead = new ListNode (0);        Myhead->next = head;        listnode* pre = Myhead;        listnode* one = head, *two = head;            while (Two->next!=null && two->next->next!=null) {pre = pre->next;            one = one->next;        both = two->next->next;        } one->next;        Pre->next = NULL;        treenode* root = new TreeNode (one->val);        Root->left = Sortedlisttobst (Myhead->next); Root->right = Sortedlisttobst(a);    Pre->next = one; Restore the linked list structure//delete one;        Why can't I delete it here?        Delete Myhead;    return root; }};

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[Leetcode] Convert Sorted List to Binary Search Tree