最小高度树
给定一个有序整数数组,元素各不相同且按升序排列,编写一个算法,创建一棵高度最小的二叉搜索树。
示例:
给定有序数组: [-10,-3,0,5,9],
一个可能的答案是:[0,-3,9,-10,null,5],它可以表示下面这个高度平衡二叉搜索树:
0 / \ -3 9 / / -10 5
示例代码:
# 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 sorted_array_to_bst(self, nums):
"""
:type nums: List[int]
:rtype: TreeNode
"""
if not nums:
return
mid = len(nums) // 2
root = TreeNode(nums[mid])
root.left = self.sorted_array_to_bst(nums[:mid])
root.right = self.sorted_array_to_bst(nums[mid + 1:])
return root
def print_tree(self, root):
"""
中序遍历
:return:
"""
if not root:
return
self.print_tree(root.left)
print(root.val, end=' ')
self.print_tree(root.right)
# test
li = [-10, -3, 0, 5, 9]
tree = Solution()
root = tree.sorted_array_to_bst(li)
tree.print_tree(root)
运行结果: