226. Invert Binary Tree
Easy
Given the
root of a binary tree, invert the tree, and return its root.Example 1:
Input: root = [4,2,7,1,3,6,9]
Output: [4,7,2,9,6,3,1]
Example 2:
Input: root = [2,1,3]
Output: [2,3,1]
Example 3:
Input: root = []
Output: []
Constraints:
- The number of nodes in the tree is in the range
[0, 100]. -100 <= Node.val <= 100
/**
* Definition for a binary tree node.
* type TreeNode struct {
* Val int
* Left *TreeNode
* Right *TreeNode
* }
*/
func invertTree(root *TreeNode) *TreeNode {
invert(root)
return root
}
func invert(root *TreeNode) {
if root != nil {
invert(root.Left)
invert(root.Right)
root.Left, root.Right = root.Right, root.Left
}
}