算法描述：
Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.
For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.
Example:
Given the sorted linked list: [-10,-3,0,5,9],
One possible answer is: [0,-3,9,-10,null,5], which represents the following height balanced BST:
0
/ -3 9
/ /
-10 5
解题思路：理解原理
TreeNode* sortedListToBST(ListNode* head) { if(head == nullptr) return nullptr; return helper(head,nullptr); } TreeNode* helper(ListNode* start, ListNode* end){ if(start==end) return nullptr; ListNode* fast = start; ListNode* slow = start; while(fast->next!=end && fast->next->next!=end){ fast = fast->next->next; slow = slow->next; } TreeNode* node = new TreeNode(slow->val); node->left = helper(start,slow); node->right = helper(slow->next,end); return node; }
LeetCode-109-Convert Sorted List to Binary Search Tree
原文：https://www.cnblogs.com/nobodywang/p/10349596.html