Invert Binary Tree
Given the root of a binary tree, invert the tree, and return its root.
Example 1
4 4
/ \ / \
2 7 -> 7 2
/ \ / \ / \ / \
1 3 6 9 9 6 3 1Input
root = [4,2,7,1,3,6,9]Output
[4,7,2,9,6,3,1]The left and right children are swapped recursively throughout the tree, producing
[4,7,2,9,6,3,1].Example 2
2 2
/ \ -> / \
1 3 3 1Input
root = [2,1,3]Output
[2,3,1]The left and right children of the root are swapped, producing
[2,3,1].Constraints
- The number of nodes in the tree is in the range
[0, 100]. -100 <= Node.val <= 100