Question:
Invert a binary tree.
4
/ \
2 7
/ \ /
1 3 6 9
to
4
/ \
7 2
/ \ /
9 6 3 1
Solution:
public class Solution {
public TreeNode invertTree(TreeNode root) {
if(root==null) return root;
root.left=invertTree(root.left);
root.right=invertTree(root.right);
TreeNode temp=root.left;
root.left=root.right;
root.right=temp;
return root;
}
}