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# Time: O(n)

# Space: O(n)

# Given an integer array with no duplicates.

# A maximum tree building on this array is defined as follow:

#

# The root is the maximum number in the array.

# The left subtree is the maximum tree constructed from left part subarray divided by the maximum number.

# 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.

#

# 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:

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

# 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 constructMaximumBinaryTree(self, nums):

"""

:type nums: List[int]

:rtype: TreeNode

"""

# https://github.com/kamyu104/LintCode/blob/master/C++/max-tree.cpp

nodeStack = []

for num in nums:

node = TreeNode(num);

while nodeStack and num > nodeStack[-1].val:

node.left = nodeStack.pop()

if nodeStack:

nodeStack[-1].right = node

nodeStack.append(node)

return nodeStack[0]