Convert Sorted List to Balanced Binary Search Tree (BST)

(http://leetcode.com/2010/11/convert-sorted-list-to-balanced-binary.html)

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

Code:

BinaryTree* sortedListToBST(ListNode *& list, int start, int end)
{
    if (start > end)
        return NULL;
    int mid = start + (end - start) / 2;
    BinaryTree* leftChild = sortedListToBST(list, start, mid-1);
    BinaryTree* parent = new BinaryTree(list->data);
    parent->left = leftChild;
    list = list->next;
    parent->right = sortedListToBST(list, mid+1, end);
    return parent;
}

BinaryTree* sortedListToBST(ListNode* head, int n)
{
    return sortedListToBST(head, 0, n-1);
}