Convert Sorted List to Binary Search Tree.py

__author__ = 'Martin'

class ListNode(object):
    def __init__(self, x):
        self.val = x
        self.next = None

class TreeNode(object):
    def __init__(self, x):
        self.val = x
        self.left = None
        self.right = None

class Solution(object):
    def sortedListToBST(self, head):
        """
        :type head: ListNode
        :rtype: TreeNode
        """