/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode() : val(0), next(nullptr) {}
* ListNode(int x) : val(x), next(nullptr) {}
* ListNode(int x, ListNode *next) : val(x), next(next) {}
* };
*/
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
TreeNode* sortedListToBST(ListNode* head) {
vector<int> nums;
for(auto p = head;p;p=p->next) nums.push_back(p->val);
if(nums.size() == 0) return NULL;
return build(nums,0,nums.size() - 1);
}
TreeNode* build(vector<int>& nums,int l,int r) {
if(l > r) return NULL;
int mid = l + r >> 1;
auto root = new TreeNode(nums[mid]);
root->left = build(nums,l,mid - 1);
root->right = build(nums,mid+1,r);
return root;
}
};