Invert a Binary Tree

In an inverted binary tree, each node in the original is swapped with the corresponding node on the other side.

You can also think of it as rotating the tree on an axis right down the middle.

Example:

Here's the same tree, inverted.

Like most tree problems, it's best handled recursively. You just

• Swap
• Recurse to the left child
• Recurse to the right child

def invertBinaryTree(tree):
    # This is why I use Python for stuff like this
	tree.left,tree.right = tree.right,tree.left

    if (tree.left is not None):
		invertBinaryTree(tree.left)
	if (tree.right is not None):
		invertBinaryTree(tree.right)



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

It's surprisingly simple.