Tnode* convert2BST(List *head)
{
if(head==NULL)
return NULL;
List *middle,*l,*r;
getmiddleNsplit(l,middle,r);
Tnode* root=(Tnode*)malloc(sizeof(Tnode));
Tnode->data=middle->data;
Tnode->left=convert2BST(l);
Tnode->right=convert2BST(r);
}
TreeNode *convert2BST(ListNode *&head, int start, int end) {
if(start > end)
return NULL;
int mid = (start + end) / 2;
TreeNode *left = convert2BST(head, start, mid - 1);
TreeNode *node = new TreeNode(head->val);
head = head->next;
TreeNode *right = convert2BST(head, mid + 1, end);
node->left = left;
node->right = right;
return node;
}
TreeNode *sortedListToBST(ListNode *head) {
int n = 0;
ListNode *iter = head;
while(iter) {
n ++;
iter = iter->next;
}
return convert2BST(head, 0, n - 1);
}
