Mirror Binary Tree

Mirror the given binary tree. That is, right child of every nodes should become left and left should become right.

Note : You don't need to print or return the tree, just mirror it.

Input format :

Line 1 : Elements in level order form (separated by space)

(If any node does not have left or right child, take -1 in its place)

Output format : Elements in level order form (Every level in new line)

Sample Input 1:

1 2 3 4 5 6 7 -1 -1 -1 -1 -1 -1 -1 -1

Sample Output 1:

1 
3 2 
7 6 5 4

Sample Input 2:

5 10 6 2 3 -1 -1 -1 -1 -1 9 -1 -1

Sample Output 2:

5 
6 10 
3 2 
9

	import queue
	class BinaryTreeNode:
	def __init__(self, data):
	self.data = data
	self.left = None
	self.right = None
	def mirrorBinaryTree(root):
	if root == None:
	return None
	if root.left == None and root.right == None:
	return None
	mirrorBinaryTree(root.left)
	mirrorBinaryTree(root.right)
	temp = root.left
	root.left = root.right
	root.right = temp
	return root
	def buildLevelTree(levelorder):
	index = 0
	length = len(levelorder)
	if length<=0 or levelorder[0]==-1:
	return None
	root = BinaryTreeNode(levelorder[index])
	index += 1
	q = queue.Queue()
	q.put(root)
	while not q.empty():
	currentNode = q.get()
	leftChild = levelorder[index]
	index += 1
	if leftChild != -1:
	leftNode = BinaryTreeNode(leftChild)
	currentNode.left =leftNode
	q.put(leftNode)
	rightChild = levelorder[index]
	index += 1
	if rightChild != -1:
	rightNode = BinaryTreeNode(rightChild)
	currentNode.right =rightNode
	q.put(rightNode)
	return root
	# Problem ID 353, Level order traversal
	def printLevelATNewLine(root):
	# Given a binary tree, print the level order traversal. Make sure each level
	# start in new line.
	if root==None:
	return
	inputQ = queue.Queue()
	outputQ = queue.Queue()
	inputQ.put(root)
	while not inputQ.empty():
	while not inputQ.empty():
	curr = inputQ.get()
	print(curr.data, end=' ')
	if curr.left!=None:
	outputQ.put(curr.left)
	if curr.right!=None:
	outputQ.put(curr.right)
	print()
	inputQ, outputQ = outputQ, inputQ
	# Main
	levelOrder = [int(i) for i in input().strip().split()]
	root = buildLevelTree(levelOrder)
	mirrorBinaryTree(root)
	printLevelATNewLine(root)

view raw Mirror Binary Tree.py hosted with ❤ by GitHub