1008. Construct Binary Search Tree from Preorder Traversal

构造一棵BST要求前序遍历等于给定的序列

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution(object):
    def bstFromPreorder(self, preorder):
        """
        :type preorder: List[int]
        :rtype: TreeNode
        """
        if not preorder:
            return None
        root = TreeNode(preorder[0])
        i = bisect.bisect(preorder, preorder[0])
        root.left = self.bstFromPreorder(preorder[1:i])
        root.right = self.bstFromPreorder(preorder[i:])
        return root
        

乱七八糟，java没实现