Given a binary tree, invert the binary tree and return it.
Look at the example for more details.
Given binary tree
1 / \ 2 3 / \ / \ 4 5 6 7
invert and return
1 / \ 3 2 / \ / \ 7 6 5 4
NOTE: You only need to implement the given function. Do not read input, instead use the arguments to the function. Do not print the output, instead return values as specified. Still have a doubt? Checkout Sample Codes for more details.