【leetcode】654. Maximum Binary Tree

题目如下：

解题思路：题目不难，从72%通过率就能看出来。方法是找出数组的最大值并作为根节点，然后把数组以最大值为界分成左右两部分；之后再对左右两部分分别递归，直到数组被分割完成为止。

代码如下：

# 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 build(self,node,nums):

        v = max(nums)

        inx = nums.index(v)

        node.val = v

        ll = nums[:inx]

        rl = nums[inx+1:]

        if len(ll) > 0:

            left = TreeNode(None)

            node.left = left

            self.build(left,ll)

        if len(rl) > 0:

            right = TreeNode(None)

            node.right = right

            self.build(right,rl)

    def constructMaximumBinaryTree(self, nums):

        """

        :type nums: List[int]

        :rtype: TreeNode

        """

        root = TreeNode(None)

        self.build(root,nums)

        return root