106. The sorted list is converted to a two-point lookup tree

106. The sorted list is converted to a two -point lookup tree

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Gives a single linked list of all elements in ascending order, converting it into a highly balanced binary search tree

Have you ever encountered this problem in a real interview? Yes Sample Example

               21->2->3  =>   /              1   3

label  Links List   recursion  

/** * Definition of ListNode * class ListNode {* Public: * int val; * ListNode *next; * ListNode (int val) {* This->val = val; * This->next = NULL; *} *} * Definition of TreeNode: * Class TreeNode {* Public: * int val; * TreeNode *left, *right; * Tree Node (int val) {* This->val = val; * This->left = This->right = NULL; *} *} */class Solutio     n {public:/** * @param head:the first node of linked list.     * @return: A tree node */TreeNode *sortedlisttobst (ListNode *head) {//write your code here//with recursion    treenode* root = nullptr;    if (head! = nullptr) {ListNode *left = nullptr, *right = nullptr;    root = new TreeNode (Dichotomylist (head, left, right));    Root->left = Sortedlisttobst (left);    Root->right = Sortedlisttobst (right); }} int Dichotomylist (ListNode *head, ListNode *&left, ListNode *&right) {if (Head->next! = Nullpt   R {ListNode *fast = head, *slow = head, *temp = head;    while (fast! = nullptr && Fast->next! = nullptr) {temp = slow;    slow = slow->next;    Fast = fast->next->next;    } temp->next = nullptr;    left = head;    right = slow->next;    Return slow->val;    } else {left = nullptr;    right = nullptr;    Return head->val; }    }};

　　

106. The sorted list is converted to a two-point lookup tree