python寫算法題：leetcode: 109. Convert Sorted List to Binary Search Tree

class Solution(object):
    def sortedArrayToBST(self, nums):
        """
        :type nums: List[int]
        :rtype: TreeNode
        """
        if len(nums)==0: return None
        pos=len(nums)/2
        root=TreeNode(nums[pos])
        root.left=self.sortedArrayToBST(nums[:pos])
        root.right=self.sortedArrayToBST(nums[pos+1:])
        return root
    def sortedListToBST(self, head):
        """
        :type head: ListNode
        :rtype: TreeNode
        """
        nums=[]
        
        node = head
        while node!=None:
            nums.append(node.val)
            node=node.next
        return self.sortedArrayToBST(nums)