LeetCode刷题（C++）——Convert Sorted List to Binary Search Tree（Normal）

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

/** * 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;if (head->next == NULL)return new TreeNode(head->val);ListNode prenode(0);ListNode* pre = &prenode;pre->next = head;ListNode* one = head;               //用来循环指向中间结点，即子树根结点ListNode* two = head;while (two && two->next)            //查找子树根结点{pre = pre->next;one = one->next;two = two->next->next;}TreeNode* root = new TreeNode(one->val);ListNode* temp = one->next;pre->next = NULL;                          //将左子树和根结点断开one->next = NULL;                          //将右子树和根结点断开root->left = sortedListToBST(head);root->right = sortedListToBST(temp);return root;    }};