python leetcode 654. Maximum Binary Tree

Given an integer array with no duplicates. A maximum tree building on this array is defined as follow:

1. The root is the maximum number in the array.
2. The left subtree is the maximum tree constructed from left part subarray divided by the maximum number.
3. The right subtree is the maximum tree constructed from right part subarray divided by the maximum number.

Construct the maximum tree by the given array and output the root node of this tree.

列表中的最大值为二叉树的root，左子树为列表最大值左侧中的最大值，右子树为列表最大值右侧中的最大值。

Example 1:

Input: [3,2,1,6,0,5]
Output: return the tree root node representing the following tree:

      6
    /   \
   3     5
    \    / 
     2  0   
       \
        1

Note:

1. The size of the given array will be in the range [1,1000].

class Solution:
    def constructMaximumBinaryTree(self, nums):
        """
        :type nums: List[int]
        :rtype: TreeNode
        """
        if nums == []:
            return None
        maxNode = max(nums)
        maxindex = nums.index(maxNode)
        root = TreeNode(maxNode)
        root.left = self.constructMaximumBinaryTree(nums[: maxindex])
        root.right = self.constructMaximumBinaryTree(nums[maxindex+1 :])
        return root