每日算法题: Get all Values at a Certain Height in a Binary Tree

Hi, here's your problem today. This problem was recently asked by Amazon:

Given a binary tree, return all values given a certain height h.

Here's a starting point:

class Node():

  def __init__(self, value, left=None, right=None):

    self.value = value

    self.left = left

    self.right = right



def valuesAtHeight(root, height):

  # Fill this in.



#     1

#    / \

#   2   3

#  / \   \

# 4   5   7



a = Node(1)

a.left = Node(2)

a.right = Node(3)

a.left.left = Node(4)

a.left.right = Node(5)

a.right.right = Node(7)

print valuesAtHeight(a, 3)

# [4, 5, 7]